The Hedgerows Regulations 1997 - Waverley Council · Removal of hedgerows 5 . - (1) Subject to the exceptions specified in regulation 6, the removal[15] of a hedgerow to which these

SDPNT Poe 2.5 - Extract From The Hedgerow Regulations

Statutory Instrument 1997 No. 1160

The Hedgerows Regulations 1997

© Crown Copyright 1997

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STATUTORY INSTRUMENTS

1997 No. 1160

COUNTRYSIDE

The Hedgerows Regulations 1997

Made 24th March 1997

Coming into force 1st June 1997

ARRANGEMENT OF REGULATIONS 1. Citation and commencement 2. Interpretation 3. Application of Regulations 4. Criteria for determining "important" hedgerows 5. Removal of hedgerows 6. Permitted work 7. Offences 8. Replacement of hedgerows 9. Appeals

10. Records 11. Injunctions 12. Rights to enter without a warrant 13. Right to enter under warrant 14. Rights of entry: supplementary provisions 15. Local planning authorities as owners of hedgerows 16. Application of other provisions of the 1990 Act

SCHEDULES

1. Additional criteria for determining "important" hedgerows

2. Woodland species 3. Woody species 4. Form of hedgerow removal notice The Secretary of State for the Environment and the Minister of Agriculture, Fisheries and Food, acting jointly as respects England, and the Secretary of State for Wales, as respects Wales, in exercise of the powers conferred by section 97 of the Environment Act 1995[1], and of all other powers enabling them in that behalf, having undertaken the


consultations required by section 97(6) of that Act, hereby make the following Regulations, a draft of which has been laid before, and has been approved by resolution of, both Houses of Parliament: Citation and commencement 1 . These Regulations may be cited as the Hedgerows Regulations 1997 and shall come into force on 1st June 1997. Interpretation 2 . - (1) In these Regulations -

"the 1990 Act" means the Town and Country Planning Act 1990[2]; "the 1995 Act" means the Environment Act 1995; "agriculture" includes horticulture, fruit growing, seed growing, dairy farming, the breeding and keeping of livestock (including any creature kept for the production of food, wool, skins or fur, or for the purposes of its use in the farming of land), the use of land as grazing land, meadow land, osier land, market gardens and nursery grounds, and the use of land for woodlands where that use is ancillary to the farming of land for other agricultural purposes, and "agricultural" shall be construed accordingly; "agricultural holding" has the same meaning as in the Agricultural Holdings Act 1986[3]; "common land" has the same meaning as in the Commons Registration Act 1965[4], and references to common land include town or village green within the meaning of that Act; "farm business tenancy" has the same meaning as in the Agricultural Tenancies Act 1995[5]; "gap", in relation to a hedgerow[6], means any opening (whether or not it is filled); "hedgerow removal notice" means a notice under regulation 5(1)(a); "hedgerow retention notice" means a notice referred to in regulation 5(2); "local planning authority", except in paragraph 5(b)(ii) of Part II of Schedule 1, means - (a) as regards land within a National Park, the National Park Authority for that Park[7], (b) as regards land within the Broads, within the meaning of the Norfolk and Suffolk Broads Act 1988, the Broads Authority[8], (c) as regards the Isles of Scilly, the Council of the Isles of Scilly, (d) as regards any other land in England, the district planning authority within the meaning of the 1990 Act, (e) as regards any other land in Wales, the county council or


county borough council;

"notice" means notice in writing; "owner" - (a) in relation to a hedgerow growing on any land which comprises part of an agricultural holding or which is subject to a farm business tenancy, means the person who owns the freehold of the land or the tenant; (b) in relation to a hedgerow growing on any other land, means the person who owns the freehold of the land,

and "owns the freehold" means is entitled, otherwise than as a mortgagee not in possession, to dispose of the fee simple;

"protected land" means - (a) land managed as a nature reserve in pursuance of section 21 (establishment of nature reserves by local authorities) of the National Parks and Access to the Countryside Act 1949[9], (b) land in relation to which a notification under section 28 (areas of special scientific interest) of the Wildlife and Countryside Act 1981[10] is in force; "relevant utility operator", in relation to any hedgerow, means - (a) any person who holds a licence granted under section 6 of the Electricity Act 1989[11] (power to grant licences for the generation, transmission or supply of electricity) and who wishes to remove or, as the case may be, removes the hedgerow in question for the purpose of carrying out any activity authorised by that licence; (b) any person who holds a licence granted or treated as granted under section 7 of the Gas Act 1986[12] (power to grant licences for the conveyance of gas through pipes) and who wishes to remove or, as the case may be, removes the hedgerow in question for the purpose of carrying out any activity authorised by that licence; (c) any person who holds a licence granted under section 7 of the Telecommunications Act 1984[13] (power to licence telecommunications systems) which applies to him the telecommunications code contained in Schedule 2 to that Act and who wishes to remove or, as the case may be, removes the hedgerow in question in pursuance of a right conferred by the telecommunications code and in accordance with the provisions of his licence; (d) a sewerage undertaker or a water undertaker which wishes to


remove or, as the case may be, removes the hedgerow in question for the purpose of carrying out its functions, within the meaning of the Water Industry Act 1991[14].

(2) In these Regulations a reference to a numbered regulation or Schedule is to the regulation in, or Schedule to, these Regulations which is so numbered and a reference in a regulation or Schedule to a numbered paragraph, or in a paragraph to a numbered sub-paragraph, is to a paragraph or sub-paragraph of that regulation, Schedule or paragraph. (3) Part I of Schedule 1 shall have effect for the purposes of interpretation of that Schedule, and Schedules 2 and 3 shall have effect for the purposes of that Part. Application of Regulations 3 . - (1) Subject to paragraph (3), these Regulations apply to any hedgerow growing in, or adjacent to, any common land, protected land, or land used for agriculture, forestry or the breeding or keeping of horses, ponies or donkeys, if -

(a) it has a continuous length of, or exceeding, 20 metres; or (b) it has a continuous length of less than 20 metres and, at each end, meets (whether by intersection or junction) another hedgerow.

(2) Subject to paragraph (3), a hedgerow is also one to which these Regulations apply if it is a stretch of hedgerow forming part of a hedgerow such as is described in paragraph (1). (3) These Regulations do not apply to any hedgerow within the curtilage of, or marking a boundary of the curtilage of, a dwelling-house. (4) A hedgerow which meets (whether by intersection or junction) another hedgerow is to be treated as ending at the point of intersection or junction. (5) For the purposes of ascertaining the length of any hedgerow -

(a) any gap resulting from a contravention of these Regulations; and (b) any gap not exceeding 20 metres,

shall be treated as part of the hedgerow. Criteria for determining "important" hedgerows 4 . For the purposes of section 97 (hedgerows) of the Environment Act 1995 and these Regulations, a hedgerow is "important" if it, or the


hedgerow of which it is a stretch, -

(a) has existed for 30 years or more; and (b) satisfies at least one of the criteria listed in Part II of Schedule 1.

Removal of hedgerows 5 . - (1) Subject to the exceptions specified in regulation 6, the removal[15] of a hedgerow to which these Regulations apply is prohibited unless -

(a) the local planning authority in whose area the hedgerow is situated or, where it is situated in the area of more than one such authority, the local planning authority in whose area the greater part of the hedgerow is situated, have received from an owner of the hedgerow (subject to paragraph (10)) notice in the form set out in Schedule 4, or a form substantially to the same effect, of his proposal to remove the hedgerow ("hedgerow removal notice") together with the plan and evidence mentioned in the form set out in Schedule 4; and (b)

(i) the authority have given to the person who gave the hedgerow removal notice written notice stating that the hedgerow may be removed; or (ii) the period specified in paragraph (6) has expired without the authority having given to that person a hedgerow retention notice stating that the work may not be carried out; and

(c) the removal is carried out in accordance with the proposal specified in the hedgerow removal notice; and (d) the hedgerow is removed within the period of two years beginning with the date of service of the hedgerow removal notice.

(2) A local planning authority which has received a hedgerow removal notice shall, consistently with paragraph (5) and within the period specified in paragraph (6), decide whether or not to give notice to that person stating that the work or, where the hedgerow removal notice refers to more than one hedgerow, so much of the work as may be specified by the authority in their notice, may not be carried out ("hedgerow retention notice"). (3) Where a hedgerow in respect of which the local planning authority has received a hedgerow removal notice is situated in a parish in England for which there is a parish council, or in a community in Wales for which


there is a community council, that authority shall consult that council (or, where there is more than one such council, each of them) on the proposal to remove that hedgerow. (4) The consultation referred to in paragraph (3) shall be completed before the period specified in paragraph (6) expires and before the giving of a notice under paragraph (1)(b)(i) or a hedgerow retention notice. (5) A local planning authority -

(a) shall not give a hedgerow retention notice in respect of a hedgerow which is not an "important" hedgerow; (b) shall give such a notice, within the period specified in paragraph (6), in respect of an "important" hedgerow unless satisfied, having regard in particular to the reasons given for its proposed removal in the hedgerow removal notice, that there are circumstances which justify the hedgerow's removal.

(6) The period referred to in paragraphs (1)(b)(ii), (2), (4) and (5)(b) is that of 42 days beginning with the date on which the hedgerow removal notice is received by the local planning authority or such longer period as may be agreed between the person who gave the notice and the authority. (7) A hedgerow retention notice shall, except where regulation 8(4) applies, specify each criterion (of those listed in Schedule 1) which applies to the hedgerow to which the notice relates. (8) A hedgerow retention notice may be withdrawn at any time by the local planning authority by giving written notice of the withdrawal to the person to whom the hedgerow retention notice was given. (9) Where a hedgerow retention notice has been given stating that work relating to a hedgerow may not be carried out, and that notice has not been withdrawn, removal of the hedgerow consisting of or including any such work is prohibited. (10) Where a hedgerow is or is to be removed by or on behalf of a relevant utility operator from land of which it is not the owner, paragraph (1)(a) shall apply as though the reference to the owner were instead a reference to the relevant utility operator. Permitted work 6 . - (1) The removal of any hedgerow to which these Regulations apply is permitted if it is required -

(a) for making a new opening in substitution for an existing opening which gives access to land, but subject to paragraph (2); (b) for obtaining temporary access to any land in order to give


assistance in an emergency; (c) for obtaining access to land where another means of access is not available or is available only at disproportionate cost; (d) for the purposes of national defence; (e) for carrying out development for which planning permission has been granted or is deemed to have been granted, except development for which permission is granted by article 3 of the Town and Country Planning General Permitted Development Order 1995[16] in respect of development of any of the descriptions contained in Schedule 2 to that Order other than Parts 11 (development under local or private Acts or orders) and 30 (toll road facilities); (f) for carrying out, pursuant to, or under, the Land Drainage Act 1991[17], the Water Resources Act 1991[18] or the Environment Act 1995[19], work for the purpose of flood defence or land drainage; (g) for preventing the spread of, or ensuring the eradication of -

(i) any plant pest, within the meaning of the Plant Health (Great Britain) Order 1993[20], in respect of which any action is being, or is to be, taken under Article 22 or 23 of that Order, or (ii) any tree pest, within the meaning of the Plant Health (Forestry) (Great Britain) Order 1993[21], in respect of which any action is being, or is to be, taken under Article 21 or 22 of that Order;

(h) for the carrying out by the Secretary of State of his functions in respect of any highway for which he is the highway authority[22] or in relation to which, by virtue of section 4(2) of the Highways Act 1980, he has the same powers under that Act as the local highway authority; (i) for carrying out any felling, lopping or cutting back required or permitted as a consequence of any notice given or order made under paragraph 9 of Schedule 4 to the Electricity Act 1989[23] (felling, lopping or cutting back to prevent obstruction of or interference with electric lines and plant or to prevent danger); or (j) for the proper management of the hedgerow.

(2) Where the removal of a hedgerow to which these Regulations apply is permitted by these Regulations only by paragraph (1)(a), the person removing it shall fill the existing opening by planting a hedge within 8


months of the making of the new opening. (3) The fact that work is permitted under these Regulations does not affect any prohibition or restriction imposed by or under any other enactment or by any agreement. Offences 7 . - (1) A person who intentionally or recklessly removes, or causes or permits another person to remove, a hedgerow in contravention of regulation 5(1) or (9) is guilty of an offence. (2) A person who contravenes or fails to comply with regulation 6(2) is guilty of an offence. (3) Hedgerows to which these Regulations apply are prescribed for the purposes of section 97(4)(d) of the 1995 Act (which relates to offences triable either way). (4) A person guilty of an offence under paragraph (1) shall be liable -

(a) on summary conviction, to a fine not exceeding the statutory maximum; or (b) on conviction on indictment, to a fine.

(5) A person guilty of an offence under paragraph (2) shall be liable on summary conviction to a fine not exceeding level 3 on the standard scale. (6) In determining the amount of any fine to be imposed on a person convicted of an offence under paragraph (1) or (2), the court shall in particular have regard to any financial benefit which has accrued or appears likely to accrue to him in consequence of the offence. (7) Section 331 (offences by corporations) of the 1990 Act shall apply in relation to offences under paragraph (1) or (2) committed by a body corporate as it applies in relation to offences under that Act committed by a body corporate. Replacement of hedgerows 8 . - (1) Subject to regulation 15, where it appears to the local planning authority that a hedgerow has been removed in contravention of regulation 5(1) or (9), the authority may (whether or not proceedings are instituted under regulation 7), give a notice to the owner, requiring him to plant another hedgerow or, where the hedgerow has been removed by or on behalf of a relevant utility operator, give a notice to that operator requiring it to plant another hedgerow. (2) A notice under paragraph (1) shall specify the species and position of the shrubs, or trees and shrubs, to be planted and the period within which the planting is to be carried out.


(3) Subsections (1), (2) and (6) of section 209 (execution and cost of works required by s.207 notice) of the 1990 Act shall apply, with the necessary modifications, to shrubs and trees whose planting is required by a notice under paragraph (1) as if they were trees whose planting was required by a notice under subsection (1) of section 207 (enforcement of duties as to replacement of trees) of that Act. (4) A hedgerow planted in compliance with a notice under paragraph (1) or by virtue of paragraph (3) shall be treated -

(a) for the purposes of these Regulations; (b) for the period of 30 years beginning with the date of substantial completion of the planting,

as if it were an "important" hedgerow within the meaning of regulation 4. Appeals 9 . - (1) Subject to regulation 15, a person to whom a hedgerow retention notice or a notice under regulation 8(1) is given may, by notice given within 28 days from the date on which the notice was given to him, or such longer period as the Secretary of State may allow, appeal to the Secretary of State. (2) The notice of appeal shall state the grounds for the appeal and the appellant shall serve a copy of it on the local planning authority which gave the hedgerow retention notice or notice under regulation 8(1). (3) In determining the appeal the Secretary of State -

(a) may allow or dismiss it, either as to the whole or as to part; (b) shall give any directions necessary to give effect to his determination, including directions for quashing or modifying any notice,

and he shall notify the appellant and the local planning authority of his determination of the appeal. (4) Before determining the appeal, the Secretary of State shall afford to the appellant and the local planning authority an opportunity, if they so wish, of appearing before, and being heard by, a person appointed by the Secretary of State for the purpose. (5) The Secretary of State may cause a local inquiry to be held in connection with an appeal and subsections (2) to (5) of section 250 of the Local Government Act 1972 (local inquiries: evidence and costs) shall apply to any such inquiry.


(6) The Secretary of State shall have the same powers to appoint a person to exercise functions in connection with appeals under this regulation as he is given by section 114 of the 1995 Act in relation to his functions specified in that section; and the provisions of Schedule 20 to that Act shall apply with respect to any such appointment as it applies to appointments under that section. (7) The Secretary of State and any person appointed by him for any purpose of this regulation shall, except where the appeal is disposed of on the basis of written representations and other documents, have the same power to make orders under section 250(5) of the Local Government Act 1972 (orders with respect to costs of the parties) in relation to proceedings on an appeal under this regulation which do not give rise to an inquiry as he has in relation to an inquiry and section 322A[24] (orders as to costs: supplementary) of the 1990 Act shall apply to proceedings on an appeal under this regulation as if they were proceedings under that Act. Records 10 . Each local planning authority shall compile and keep available for public inspection free of charge at all reasonable hours and at a convenient place a record containing a copy of -

(a) every hedgerow removal notice received by them; (b) every hedgerow retention notice issued by them; (c) every notice given by them under regulation 5(1)(b)(i); (d) every determination notified to them under regulation 9(3).

Injunctions 11 . - (1) Where a local planning authority consider it necessary or expedient for an actual or apprehended offence under these Regulations to be restrained by injunction, they may apply to the court for an injunction, whether or not they have exercised or are proposing to exercise any of their other powers under these Regulations. (2) On an application under paragraph (1) the court may grant such an injunction as the court thinks appropriate for the purpose of restraining the offence. (3) In this regulation "the court" means the High Court or the county court. Rights to enter without a warrant 12 . - (1) Any person duly authorised in writing by a local planning authority may enter any land for the purpose of -

(a) surveying it in connection with any hedgerow removal notice received by the authority;


(b) ascertaining whether an offence under regulation 7 has been committed; (c) determining whether a notice should be given under regulation 8,

if there are reasonable grounds for entering for the purpose in question. (2) Any person duly authorised in writing by the Secretary of State may enter any land for the purpose of surveying it in connection with any appeal made under regulation 9, if there are reasonable grounds for entering for that purpose. (3) Any right to enter by virtue of paragraph (1) or (2) shall be exercised at a reasonable hour. (4) No right to enter by virtue of paragraph (1)(a) or (2) shall be exercised in relation to land which -

(a) adjoins that in respect of which a hedgerow removal notice has been given or an appeal made; and (b) is occupied by a person other than the person who gave the hedgerow removal notice or made the appeal,

unless at least 24 hours' notice of the intended entry has been given to the occupier of that adjoining land. (5) In a case to which regulation 5(10) applies, no right to enter any land by virtue of paragraph (1)(a) or (2) shall be exercised unless at least 24 hours' notice of the intended entry has been given to the occupier of the land. Right to enter under warrant 13 . - (1) If it is shown to the satisfaction of a justice of the peace on sworn information in writing -

(a) that there are reasonable grounds for entering any land for any of the purposes mentioned in regulation 12(1) or (2); and (b) that -

(i) admission to the land has been refused, or a refusal is reasonably apprehended; or (ii) the case is one of urgency,

the justice may issue a warrant authorising any person duly authorised in writing by a local planning authority or, as the case


may be, the Secretary of State to enter the land.

(2) For the purposes of paragraph (1)(b)(i) admission to land shall be regarded as having been refused if no reply is received to a request for admission within a reasonable period. (3) A warrant authorises entry on one occasion only and that entry must be -

(a) within one month from the date of the issue of the warrant; and (b) at a reasonable hour, unless the case is one of urgency.

Rights of entry: supplementary provisions 14 . - (1) Any power conferred by virtue of regulation 12 or 13 to enter land ("a right of entry") shall be construed as including power to take samples from any hedgerow on the land and samples of the soil. (2) A person authorised to enter land in the exercise of a right of entry -

(a) shall, if so required, produce evidence of his authority and state the purpose of his entry before so entering; (b) may take with him such other persons as may be necessary; and (c) on leaving the land shall, if the occupier is not then present, leave it as effectively secured against trespassers as he found it.

(3) Any person who wilfully obstructs a person acting in the exercise of a right of entry shall be guilty of an offence and liable on summary conviction to a fine not exceeding level 3 on the standard scale. (4) If any damage is caused to land or chattels in the exercise of a right of entry, compensation may be recovered by any person suffering the damage from the authority who gave the written authority for the entry or, as the case may be, the Secretary of State. (5) Any question of disputed compensation under this regulation shall be referred to and determined by the Lands Tribunal. (6) In relation to the determination of any such question, the provisions of sections 2 and 4 of the Land Compensation Act 1961[25] shall apply subject to any necessary modifications. Local planning authorities as owners of hedgerows 15 . - (1) This regulation applies where a local planning authority are the owners (whether alone or jointly with others) of a hedgerow to which these Regulations apply.


(2) Notwithstanding anything in section 101 (arrangements for the discharge of functions by local authorities) of the Local Government Act 1972[26], a hedgerow removal notice given in a case to which this regulation applies may not be considered -

(a) by a committee or sub-committee of the authority concerned if that committee or sub-committee is responsible (wholly or partly) for the management of the land in which is situated the hedgerow to which the notice relates; or (b) by an officer of the authority concerned if his responsibilities include any aspect of the management of the land in which is situated the hedgerow to which the notice relates.

(3) Regulations 8 and 9 do not apply in a case to which this regulation applies. Application of other provisions of the 1990 Act 16 . - (1) Subsections (1), (3) and (6) of section 318 (ecclesiastical property) of the 1990 Act[27] shall apply -

(a) to notices required to be served under these Regulations on an owner of land as if those notices were notices required to be served on an owner of land under a provision of the 1990 Act; and (b) to compensation payable under regulation 14 of these Regulations as if that compensation were compensation payable under Part IV of the 1990 Act.

(2) Subsections (1), (2) and (4) of section 329 (service of notices) of the 1990 Act[28] shall apply to notices under these Regulations as if those notices were notices required or authorised to be given or served under that Act. John Selwyn Gummer Secretary of State for the Environment 23rd March 1997 Tim Boswell Paliamentary Secretary, Ministry of Agriculture, Fisheries and Food 24th March 1997 William Hague Secretary of State for Wales 21st March 1997

SCHEDULE 1


Regulations 2(3) and 4

ADDITIONAL CRITERIA FOR DETERMINING "IMPORTANT" HEDGEROWS

PART I

INTERPRETATION In this Schedule -

"building" includes structure; "Record Office" means - (a) a place appointed under section 4 of the Public Records Act 1958[29] (place of deposit of public records), (b) a place at which documents are held pursuant to a transfer under section 144A(4) of the Law of Property Act 1922[30] or under section 36(2) of the Tithe Act 1936[31], including each of those provisions as applied by section 7(1) of the Local Government (Records) Act 1962[32], or (c) a place at which documents are made available for inspection by a local authority pursuant to section 1 of the Local Government (Records) Act 1962;

"relevant date" means the date on which these Regulations are made; "Sites and Monuments Record" means a record of archaeological features and sites adopted - (a) by resolution of a local authority within the meaning of the Local Government Act 1972[33], or (b) in Greater London, by the Historic Buildings and Monuments Commission[34];

"standard tree" - (a) in the case of a multi-stemmed tree, means a tree which, when measured at a point 1.3 metres from natural ground level, has at least two stems whose diameters are at least 15 centimetres; (b) in the case of a single-stemmed tree, means a tree which, when measured at a point 1.3 metres from natural ground level, has a stem whose diameter is at least 20 centimetres;

"woodland species" means the species listed in Schedule 2; and "woody species" means the species and sub-species listed in Schedule 3, and any hybrid, that is to say, any individual plant resulting from a cross between parents of any species or sub-


species so listed, but does not include any cultivar; and

references to the documents in paragraph 6(3)(b) and (4) are to those documents as at the relevant date, without taking account of any subsequent revisions, supplements or modifications.

PART II

CRITERIA Archaeology and history 1. The hedgerow marks the boundary, or part of the boundary, of at least one historic parish or township; and for this purpose "historic" means existing before 1850. 2. The hedgerow incorporates an archaeological feature which is -

(a) included in the schedule of monuments compiled by the Secretary of State under section 1 (schedule of monuments) of the Ancient Monuments and Archaeological Areas Act 1979[35]; or (b) recorded at the relevant date in a Sites and Monuments Record.

3. The hedgerow -

(a) is situated wholly or partly within an archaeological site included or recorded as mentioned in paragraph 2 or on land adjacent to and associated with such a site; and (b) is associated with any monument or feature on that site.

4. The hedgerow -

(a) marks the boundary of a pre-1600 AD estate or manor recorded at the relevant date in a Sites and Monuments Record or in a document held at that date at a Record Office; or (b) is visibly related to any building or other feature of such an estate or manor.

5. The hedgerow -

(a) is recorded in a document held at the relevant date at a Record Office as an integral part of a field system pre-dating the Inclosure Acts[36]; or (b) is part of, or visibly related to, any building or other feature


associated with such a system, and that system -

(i) is substantially complete; or (ii) is of a pattern which is recorded in a document prepared before the relevant date by a local planning authority, within the meaning of the 1990 Act[37], for the purposes of development control within the authority's area, as a key landscape characteristic.

Wildlife and landscape 6. - (1) The hedgerow -

(a) contains species listed or categorised as mentioned in sub-paragraph (3); or (b) is referred to in a record held immediately before the relevant date by a biological record centre maintained by, or on behalf of, a local authority within the meaning of the Local Government Act 1972[38], and in a form recognised by the Nature Conservancy Council for England, the Countryside Council for Wales[39] or the Joint Nature Conservation Committee[40], as having contained any such species -

(i) in the case of animals and birds, subject to sub-paragraph (2), within the period of five years immediately before the relevant date. (ii) in the case of plants, subject to sub-paragraph (2), within the period of ten years immediately before the relevant date;

(2) Where more than one record referable to the period of five or, as the case may be, ten years before the relevant date is held by a particular biological record centre, and the more (or most) recent record does not satisfy the criterion specified in sub-paragraph (1)(b), the criterion is not satisfied (notwithstanding that an earlier record satisfies it). (3) The species referred to in sub-paragraph (1) are those -

(a) listed in Part I (protection at all times) of Schedule 1 (birds which are protected by special penalties), Schedule 5 (animals which are protected) or Schedule 8 (plants which are protected) to the Wildlife and Countryside Act 1981[41]; (b) categorised as a declining breeder (category 3) in "Red Data Birds in Britain" Batten LA, Bibby CJ, Clement P, Elliott GD and Porter RF (Eds.), published in 1990 for the Nature Conservancy Council and the Royal Society for the Protection of Birds (ISBN 0 85661 056 9 ); or


(c) categorised as "endangered", "extinct", "rare" or "vulnerable" in Britain in a document mentioned in sub-paragraph (4).

(4) The documents referred to in sub-paragraph (3)(c) are -

(a) of the books known as the British Red Data Books:

1. "Vascular Plants" Perring FH and Farrell L, 2nd Edition, published in 1983 for the Royal Society for Nature Conservation (ISBN 0 902484 04 4 ); 2. "Insects" Shirt DB (Ed.), published in 1987 for the Nature Conservancy Council (ISBN 0 86139 380 5 ); and 3. "Invertebrates other than insects" Bratton JH (Ed.), published in 1991 for the Joint Nature Conservation Committee (ISBN 1 873701 00 4); and

(b) of the books known as the Red Data Books of Britain and Ireland: "Stoneworts" Stewart NF and Church JM, published in 1992 for the Joint Nature Conservation Committee (ISBN 1 873701 24 1).

7. - (1) Subject to sub-paragraph (2), the hedgerow includes -

(a) at least 7 woody species; (b) at least 6 woody species, and has associated with it at least 3 of the features specified in sub-paragraph (4); (c) at least 6 woody species, including one of the following - black-poplar tree (Populus nigra ssp betulifolia); large-leaved lime (Tilia platyphyllos); small-leaved lime (Tilia cordata); wild service-tree (Sorbus torminalis); or (d) at least 5 woody species, and has associated with it at least 4 of the features specified in sub-paragraph (4),

and the number of woody species in a hedgerow shall be ascertained in accordance with sub-paragraph (3). (2) Where the hedgerow in question is situated wholly or partly in the


county (as constituted on 1st April 1997) of the City of Kingston upon Hull, Cumbria, Darlington, Durham, East Riding of Yorkshire, Hartlepool, Lancashire, Middlesbrough, North East Lincolnshire, North Lincolnshire, Northumberland, North Yorkshire, Redcar and Cleveland, Stockton-on-Tees, Tyne and Wear, West Yorkshire or York[42], the number of woody species mentioned in paragraphs (a) to (d) of sub-paragraph (1) is to be treated as reduced by one. (3) For the purposes of sub-paragraph (1) (and those of paragraph 8(b)) -

(a) where the length of the hedgerow does not exceed 30 metres, count the number of woody species present in the hedgerow; (b) where the length of the hedgerow exceeds 30 metres, but does not exceed 100 metres, count the number of woody species present in the central stretch of 30 metres; (c) where the length of the hedgerow exceeds 100 metres, but does not exceed 200 metres, count the number of woody species present in the central stretch of 30 metres within each half of the hedgerow and divide the aggregate by two; (d) where the length of the hedgerow exceeds 200 metres, count the number of woody species present in the central stretch of 30 metres within each third of the hedgerow and divide the aggregate by three.

(4) The features referred to in sub-paragraph (1)(b) and (d) (which include those referred to in paragraph 8(b)) are -

(a) a bank or wall which supports the hedgerow along at least one half of its length; (b) gaps which in aggregate do not exceed 10% of the length of the hedgerow; (c) where the length of the hedgerow does not exceed 50 metres, at least one standard tree; (d) where the length of the hedgerow exceeds 50 metres but does not exceed 100 metres, at least 2 standard trees; (e) where the length of the hedgerow exceeds 100 metres, such number of standard trees (within any part of its length) as would when averaged over its total length amount to at least one for each 50 metres; (f) at least 3 woodland species within one metre, in any direction, of the outermost edges of the hedgerow;


(g) a ditch along at least one half of the length of the hedgerow; (h) connections scoring 4 points or more in accordance with sub-paragraph (5); (i) a parallel hedge within 15 metres of the hedgerow.

(5) For the purposes of sub-paragraph (4)(h) a connection with another hedgerow scores one point and a connection with a pond or a woodland in which the majority of trees are broad-leaved trees scores 2 points; and a hedgerow is connected with something not only if it meets it but also if it has a point within 10 metres of it and would meet it if the line of the hedgerow continued. 8. The hedgerow -

(a) is adjacent to a bridleway or footpath, within the meaning of the Highways Act 1980[43], a road used as a public path, within the meaning of section 54 (duty to reclassify roads used as public paths) of the Wildlife and Countryside Act 1981[44], or a byway open to all traffic, within the meaning of Part III of the Wildlife and Countryside Act 1981[45], and (b) includes at least 4 woody species, ascertained in accordance with paragraph 7(3) and at least 2 of the features specified in paragraph 7(4)(a) to (g).

SCHEDULE 2 Regulation 2(3) and Schedule 1, Part I

WOODLAND SPECIES Barren strawberry (Potentilla sterilis) Bluebell (Hyacinthoides non-scriptus) Broad buckler fern (Dryopteris dilatata) Broad-leaved helleborine (Epipactis helleborine) Bugle (Ajuga reptans) Common cow-wheat (Melampyrum pratense) Common dog violet (Viola riviniana)


Common polypody (Polypodium vulgare) Dog's mercury (Mercurialis perennis) Early dog violet (Viola reichenbachiana) Early purple orchid (Orchis mascula) Enchanter's nightshade (Circaea lutetiana) Giant fescue (Festuca gigantea) Goldilocks buttercup (Ranunculus auricomus) Great bell-flower (Campanula latifolia) Greater wood-rush (Luzula sylvatica) Hairy brome (Bromus ramosus) Hairy woodrush (Luzula pilosa) Hard fern (Blechnum spicant) Hard shield fern (Polystichum aculeatum) Hart's tongue (Asplenium scolopendrium) Heath bedstraw (Galium saxatile) Herb paris (Paris quadrifolia) Herb-robert (Geranium robertianum) Lady fern (Athyrium filix-femina) Lords-and-ladies (Arum maculatum) Male fern (Dryopteris filix-mas) Moschatel (Adoxa moschatellina) Narrow buckler-fern (Dryopteris carthusiana) Nettle-leaved bell-flower (Campanula trachelium) Oxlip (Primula elatior) Pignut (Conopodium majus)


Primrose (Primula vulgaris) Ramsons (Allium ursinum) Sanicle (Sanicula europaea) Scaly male-fern (Dryopteris affinis) Small cow-wheat (Melampyrum sylvaticum) Soft shield fern (Polystichum setiferum) Sweet violet (Viola odorata) Toothwort (Lathraea squamaria) Tormentil (Potentilla erecta) Wild strawberry (Fragaria vesca) Wood anemone (Anemone nemorosa) Wood avens/Herb bennet (Geum urbanum) Wood false-brome (Brachypodium sylvaticum) Wood horsetail (Equisetum sylvaticum) Wood meadow-grass (Poa nemoralis) Wood melick (Melica uniflora) Wood millet (Millium effusum) Wood sage (Teucrium scorodonia) Wood sedge (Carex sylvatica) Wood sorrel (Oxalis acetosella) Wood speedwell (Veronica montana) Wood spurge (Euphorbia amygdaloides) Woodruff (Galium odoratum) Yellow archangel (Lamiastrum galeobdolon) Yellow pimpernel (Lysimachia nemorum)


SCHEDULE 3 Regulation 2(3) and Schedule 1, Part I

WOODY SPECIES Alder (Alnus glutinosa) Apple, crab (Malus sylvestris) Ash (Fraxinus excelsior) Aspen (Populus tremula) Beech (Fagus sylvatica) Birch, downy (Betula pubescens) Birch, silver (Betula pendula) Black-poplar (Populus nigra sub-species betulifolia) Blackthorn (Prunus spinosa) Box (Buxus sempervirens) Broom (Cytisus scoparius) Buckthorn (Rhamnus cathartica) Buckthorn, alder (Frangula alnus) Butcher's-broom (Ruscus aculeatus) Cherry, bird (Prunus padus) Cherry, wild (Prunus avium) Cotoneaster, wild (Cotoneaster integerrimus) Currant, downy (Ribes spicatum) Currant, mountain (Ribes alpinum) Dogwood (Cornus sanguinea)


Elder (Sambucus nigra) Elm (Ulmus species) Gooseberry (Ribes uva-crispa) Gorse (Ulex europaeus) Gorse, dwarf (Ulex minor) Gorse, western (Ulex gallii) Guelder rose (Viburnum opulus) Hawthorn (Crataegus monogyna) Hawthorn, midland (Crataegus laevigata) Hazel (Corylus avellana) Holly (Ilex aquilfolium) Hornbeam (Carpinus betulus) Juniper, common (Juniperus communis) Lime, large-leaved (Tilia platyphyllos) Lime, small-leaved (Tilia cordata) Maple, field (Acer campestre) Mezereon (Daphne mezereum) Oak, pedunculate (Quercus robur) Oak, sessile (Quercus petraea) Osier (Salix viminalis) Pear, Plymouth (Pyrus cordata) Pear, wild (Pyrus pyraster) Poplar, grey (Populus x canescens) Poplar, white (Populus alba) Privet, wild (Ligustrum vulgare)


Rose (Rosa species) Rowan (Sorbus aucuparia) Sea-buckthorn (Hippophae rhamnnoides) Service-tree, wild (Sorbus torminalis) Spindle (Euonymus europaeus) Spurge-laurel (Daphne laureola) Walnut (Juglans regia) Wayfaring-tree (Viburnum lantana) Whitebeam (Sorbus species) Willow (Salix species) Yew (Taxus baccata)

SCHEDULE 4 Regulation 5(1)

FORM OF HEDGEROW REMOVAL NOTICE

The Environment Act 1995

The Hedgerows Regulations 1997 To: (Name and address of local planning authority)

From: (Name and address of person giving the notice)


1. I give you notice under regulation 5(1)(a) of the above Regulations that I propose to remove the [stretch(es) of] hedgerow(s) indicated on the attached plan. (If possible, please provide a plan to a scale of 1:2500. A different scale can be used so long as it shows clearly the location and length of the hedgerow or hedgerows that you wish to remove.) 2. The reasons why I propose to remove it/them are the following: - 3. Of the [stretch(es) of] hedgerow(s) indicated, those marked with an "X" were planted less than 30 years ago. Evidence of the date of planting is attached. 4. I am/We are the owner(s) of the freehold of the land concerned. OR (please delete as appropriate) I am/We are the tenant(s) of the agricultural holding concerned. OR (please delete as appropriate) I am/We are the tenant(s) under the farm business tenancy concerned OR (please delete as appropriate) I am/act for the utility operator concerned.

(Signature of person giving notice) (Date)

EXPLANATORY NOTE

(This note is not part of the Regulations)

These Regulations make provision for the protection of important hedgerows in England and Wales. To facilitate the protection of those hedgerows, the Regulations apply to a wider class of hedgerows, described in regulation 3 (in particular to hedgerows which are 20 metres or more long or which meet another hedgerow at each end and which, in each case, are on or adjacent to land used for certain specified purposes). Before removing any hedgerow, including a stretch of hedgerow, to which these Regulations apply the owner (or in certain cases a relevant utility operator) must notify the local planning authority (regulation 5). The


hedgerow may then not be removed if the local planning authority serves a hedgerow retention notice, which may be done only if the hedgerow is important according to the criteria set out in regulation 4 and Schedules 1 to 3. The requirement for the owner (or utility operator) to notify the local planning authority does not apply to the permitted work described in regulation 6. There are provisions for criminal offences (regulation 7), replacement of hedgerows removed in contravention of the regulations (regulation 8), appeals against hedgerow retention and other notices (regulation 9), record-keeping by the local planning authority (regulation 10), enforcement by injunction (regulation 11) and rights of entry (regulations 12 to 14). There are also provisions for hedgerows owned by the local planning authority (regulation 15) and ecclesiastical property (regulation 16(1)). Some of these further provisions apply provisions of planning legislation and others make provision comparable to that to be found in the planning legislation in connection with appeals or with the preservation of trees. The criterion for determining important hedgerows set out in paragraph 6 of Part II of Schedule 1 refers to publications known as Red Data Books. Copies of those publications are available from specialist bookshops and are available for inspection between the hours of 9 a.m. and 5 p.m. Monday to Friday at the offices of the Department of the Environment, Eland House, Bressenden Place, London SW1 and of the Welsh Office at Cathay's Park, Cardiff.

Notes: [1] 1995 c.25; See the definition of the appropriate Ministers in section 97(8). back

[2] 1990 c.8. back

[3] 1986 c.5; See section 1 of that Act. back

[4] 1965 c.64; See section 22 of that Act. back

[5] 1995 c.8; See sections 1 and 2 of that Act. back

[6] Section 97(8) of the Environment Act 1995 defines hedgerow as including any stretch of hedgerow. back

[7] See Part III of the Environment Act 1995, the National Park Authorities (Wales) Order 1995 (S.I. 1995/2803, amended by S.I. 1996/534 and 1996/1224) and the National Park Authorities (England) Order 1996 (S.I. 1996/1243). back

[8] 1988 c.4. See section 1(1) and the definition of the Broads in section


2(3). back

[9] 1949 c.97. Section 21 was amended by the Local Government Act 1972 (c.70), Schedule 30, the Local Government (Scotland) Act 1973 (c.65), Schedule 29 and the Nature Conservancy Council Act 1973 (c.54), section 1(1)(b) and (7) and Schedule 1, paragraph 1. back

[10] 1981 c.69. Section 28 was amended by the Wildlife and Countryside (Amendment) Act 1985 (c.31), section 2, the Norfolk and Suffolk Broads Act 1988 (c.4), Schedule 3, paragraph 31, and the Wildlife and Countryside (Service of Notices) Act 1985 (c.59), section 1(2). back

[11] 1989 c.29. back

[12] 1986 c.44; section 7 was substituted by section 5 of the Gas Act 1995 (c.45). back

[13] 1984 c.12. back

[14] 1991 c.56. See the definitions of function and relevant undertaker in section 219(1). back

[15] See the definition of remove in section 97(8) of the Environment Act 1995. back

[16] S.I. 1995/418. back

[17] 1991 c.59. See the definition of drainage in section 72(1), as substituted by the Environment Act 1995 (c.25), section 100(2). back

[18] 1991 c.57. See the definition of drainage in section 113(1), as amended by the Environment Act 1995, section 100(1). back

[19] 1995 c.25. See, in particular, section 2(1)(a)(iii). back

[20] S.I. 1993/1320; a relevant amending instrument is S.I. 1995/1358. The definition of plant pest is contained in article 2(1) of the Order. back

[21] S.I. 1993/1283. The definition of tree pest is contained in article 2(1) of the Order. back

[22] See Part I of the Highways Act 1980 (c.66). back

[23] 1989 c.29. back

[24] Section 322A was added by the Planning and Compensation Act 1991 (c.34), section 30. back


[25] 1961 c.33. back

[26] 1972 c.70. back

[27] Section 318(3) and (6) was amended by the Planning and Compensation Act 1991, Schedule 15, paragraph 30. back

[28] Subsection (4) was inserted by the Planning and Compensation Act 1991, Schedule 7, paragraph 51. back

[29] 1958 c.51. back

[30] 1922 c.16; section 144A was inserted by the Law of Property (Amendment) Act 1924 (c.5), Schedule 2. back

[31] 1928 c.2. back

[32] 1962 c.56. back

[33] 1972 c.70. back

[34] The Commission was established by section 32 of the National Heritage Act 1993 (c.47). back

[35] 1979 c.46. back

[36] See the Short Titles Act 1896 (c.14). back

[37] See section 1 of the Town and Country Planning Act 1990, as amended by the Local Government (Wales) Act 1994 (c.19). back

[38] See the definition of local authority in section 270(1), as amended by the Local Government Act 1985 (c.51), Schedule 17 and the Local Government (Wales) Act 1994, Schedule 1, paragraphs 1 and 57. back

[39] See section 128(1) of the Environmental Protection Act 1990 (c.43); subsection (1) of section 128 was amended by the National Heritage (Scotland) Act 1991 (c.28). back

[40] See section 128(4) of the Environmental Protection Act 1990. back

[41] 1981 c.69. Schedule 5 is amended by S.I. 1988/288, 1989/906, 1991/367 and 1992/2350. back

[42] In relation to the City of Kingston upon Hull, North and North East Lincolnshire and the East Riding of Yorkshire, see S.I. 1995/600; to Darlington and Durham, see S.I. 1995/1772; to Hartlepool, Middlesbrough, Redcar and Cleveland and Stockton-on-Tees, see S.I. 1995/1747; to Lancashire, see S.I. 1996/1868; and to North Yorkshire and


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York, see S.I. 1995/610. back

[43] 1980 c.66. See the definition of bridleway and footpath in section 3. back

[44] 1981 c.69. back

[45] See the definition in section 66(1). back

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P L A N N I N G

Planning shapes the places where people live and

work and the country we live in. It plays a key role in

supporting the Government’s wider economic, social

and environmental objectives and for sustainable

communities.

Planning Policy Statement 9: Biodiversity and GeologicalConservation

August 2005

Derek Gardiner

Text Box

SDPNT PoE 2.6 – Planning Policy Statement 9

Planning Policy Statement 9: Biodiversity and Geological Conservation

© Crown Copyright 2005

Copyright in the typographical arrangement and design rests with the Crown.

Published for the Office of the Deputy Prime Minster, under licence from the Controllerof Her Majesty’s Stationery Office.

This publication excluding logos, may be reproduced free of charge in any format ormedium for research, private study of for internal circulation within an organisation. Thisis subject to it being reproduced accurately and not in a misleading context. The materialmust be acknowledged as Crown copyright and the title of the publication specified.

For any other use of this material please write to The HMSO Licensing Division, HMSO, St Clements House, 2-16 Colegate, Norwich NR3 1BQ. Fax 01603 723000 oremail: [email protected]

ISBN 0-11-75394-6

Printed in the United Kingdom for the Stationery Office

PLANNING POLICY STATEMENT 9 | Contents

The Government’s Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

National Planning Policies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Key Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Regional Spatial Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Local Development Frameworks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Sites of Biodiversity and Geological Conservation Value: . . . . . . . . . . . . . . . . . . . . . . . . 5

International Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Sites of Special Scientific Interest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Regional and Local Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Ancient Woodland and Other Important Natural Habitats . . . . . . . . . . . . . . . . . . . . . 6

Networks of Natural Habitats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Previously Developed Land . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Biodiversity within Developments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Species Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Cancellation of Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Contents

1PLANNING POLICY STATEMENT 9 | Introduction

Planning Policy Statement 9: Biodiversity and Geological Conservation

INTRODUCTION

Planning Policy Statements (PPS) set out the Government’s national policies on differentaspects of planning in England. PPS9 sets out planning policies on protection ofbiodiversity and geological conservation through the planning system. These policiescomplement, but do not replace or override, other national planning policies and shouldbe read in conjunction with other relevant statements of national planning policy. ThisPPS replaces Planning Policy Guidance Note 9 (PPG9) on nature conservation published inOctober 1994.

The policies set out in this PPS will need to be taken into account by regional planningbodies in the preparation of regional spatial strategies, by the Mayor of London in relationto the spatial development strategy for London, and by local planning authorities in thepreparation of local development documents. They may also be material to decisions onindividual planning applications.

In the context of this PPS, biodiversity is the variety of life in all its forms as discussed inthe UK Biodiversity Action Plan.1 Geological conservation relates to the sites that aredesignated for their geology and/or geomorphological importance.2

A joint Office of the Deputy Prime Minister (06/2005) and Department of Environment,Food and Rural Affairs (01/2005)3 Circular is being published to accompany this PPS. Thissets out the wide range of legislative provisions at the international and national level thatcan impact on planning decisions affecting biodiversity and geological conservation issues.A separate guide will also be published which sets out good practice in relation to planningfor biodiversity and geological conservation.

1 Biodiversity: The UK Action Plan published in 1994 – HMSO Cm 2428.

2 A list of designated sites included in the Geological Conservation Review is held by the Joint Nature Conservation Committee(JNCC), www.jncc.gov.uk/earthheritage

3 Government Circular: Biodiversity and Geological Conservation – Statutory Obligations and their Impact within the PlanningSystem (ODPM 06/2005, Defra 01/2005) available via TSO website www.tso.co.uk/bookshop

PLANNING POLICY STATEMENT 9 | The Government’s Objectives2

Working with the grain of nature: a biodiversity strategy for England 4 sets out theGovernment’s vision for conserving and enhancing biological diversity in England, togetherwith a programme of work to achieve it. It includes the broad aim that planning,construction, development and regeneration should have minimal impacts on biodiversityand enhance it wherever possible.

In moving towards this vision, the Government’s objectives for planning are:

• to promote sustainable development by ensuring that biological and geological diversityare conserved and enhanced as an integral part of social, environmental and economicdevelopment, so that policies and decisions about the development and use of landintegrate biodiversity and geological diversity with other considerations.

• to conserve, enhance and restore the diversity of England’s wildlife and geology bysustaining, and where possible improving, the quality and extent of natural habitat andgeological and geomorphological sites; the natural physical processes on which theydepend; and the populations of naturally occurring species which they support.

• to contribute to rural renewal and urban renaissance by:

– enhancing biodiversity in green spaces and among developments so that they areused by wildlife and valued by people, recognising that healthy functional ecosystemscan contribute to a better quality of life and to people’s sense of well-being; and

– ensuring that developments take account of the role and value of biodiversity insupporting economic diversification and contributing to a high quality environment.

The planning system has a significant part to play in meeting the Government’sinternational commitments and domestic policies for habitats, species and ecosystems.

The Government’s Objectives

4 Defra, 2002, available at www.defraweb/wildlife-countryside/biodiversity/index.htm

3PLANNING POLICY STATEMENT 9 | National Planning Policies

National Planning Policies

KEY PRINCIPLES

1. Regional planning bodies and local planning authorities should adhere to the following keyprinciples to ensure that the potential impacts of planning decisions on biodiversity andgeological conservation are fully considered.

(i) Development plan policies and planning decisions should be based upon up-to-dateinformation about the environmental characteristics of their areas. Thesecharacteristics should include the relevant biodiversity and geological resources ofthe area. In reviewing environmental characteristics local authorities should assessthe potential to sustain and enhance those resources.

(ii) Plan policies and planning decisions should aim to maintain, and enhance, restore oradd to biodiversity and geological conservation interests. In taking decisions, localplanning authorities should ensure that appropriate weight is attached to designatedsites of international, national and local importance; protected species; and tobiodiversity and geological interests within the wider environment.

(iii) Plan policies on the form and location of development should take a strategicapproach to the conservation, enhancement and restoration of biodiversity andgeology, and recognise the contributions that sites, areas and features, bothindividually and in combination, make to conserving these resources.

(iv) Plan policies should promote opportunities for the incorporation of beneficialbiodiversity and geological features within the design of development.

(v) Development proposals where the principal objective is to conserve or enhancebiodiversity and geological conservation interests should be permitted.

(vi) The aim of planning decisions should be to prevent harm to biodiversity andgeological conservation interests. Where granting planning permission would resultin significant harm to those interests, local planning authorities will need to besatisfied that the development cannot reasonably be located on any alternative sitesthat would result in less or no harm. In the absence of any such alternatives, localplanning authorities should ensure that, before planning permission is granted,adequate mitigation measures are put in place. Where a planning decision wouldresult in significant harm to biodiversity and geological interests which cannot beprevented or adequately mitigated against, appropriate compensation measuresshould be sought. If that significant harm cannot be prevented, adequately mitigatedagainst, or compensated for, then planning permission should be refused.

PLANNING POLICY STATEMENT 9 | National Planning Policies4

REGIONAL SPATIAL STRATEGIES

2. Regional planning bodies should liaise closely with regional biodiversity fora or equivalentbodies, English Nature or its successors and the Environment Agency to identify the currentregional and sub-regional distribution of priority habitats and species, internationally andnationally designated areas, and broad areas for habitat restoration and re-creation.Regional planning bodies should also liaise with the British Geological Survey and, whereappropriate, local Regionally Important Geological/geomorphological Sites groups ongeodiversity issues. Over time the distribution of habitats and species, andgeomorphological processes and features, will be affected by climate change and suchchange will need to be taken into account.

3. Regional spatial strategies5 should:

(i) incorporate biodiversity objectives;

(ii) address regional, sub-regional and cross-boundary issues in relation to habitats,species and geomorphological processes through criteria-based policies;

(iii) include policies to conserve and enhance biodiversity at the regional and sub-regional levels;

(iv) include targets for the restoration and re-creation of priority habitats and therecovery of priority species populations, linked to national goals; and

(v) identify suitable indicators for monitoring biodiversity.

LOCAL DEVELOPMENT FRAMEWORKS

4. Local authorities should take an integrated approach to planning for biodiversity andgeodiversity when preparing local development documents. They should ensure thatpolicies in local development documents reflect, and are consistent with, national, regionaland local biodiversity priorities and objectives (including those agreed by local biodiversitypartnerships).

5. Local development frameworks should:

(i) indicate the location of designated sites of importance for biodiversity andgeodiversity, making clear distinctions between the hierarchy of international,national, regional and locally designated sites; and

(ii) identify any areas or sites for the restoration or creation of new priority habitatswhich contribute to regional targets, and support this restoration or creation throughappropriate policies.

5 References to regional spatial strategies in this policy statement also apply to the Spatial Development Strategy for GreaterLondon, also known as the ‘London Plan’.


SITES OF BIODIVERSITY AND GEOLOGICALCONSERVATION VALUE

International Sites

6. The most important sites for biodiversity are those identified through internationalconventions and European Directives. Local planning authorities should identify these siteson proposals maps and may need to cross-refer to the statutory protection given to thesesites in the explanatory texts in local development documents. Since they enjoy statutoryprotection specific polices in respect of these sites should not be included in localdevelopment documents (see also Part I of ODPM/Defra Circular ODPM 06/2005, Defra01/2005). The Habitats Regulations do not provide statutory protection for potentialSpecial Protection Areas (pSPAs) or to candidate Special Areas of Conservation (cSACs)before they have been agreed with the European Commission. For the purposes ofconsidering development proposals affecting them, as a matter of policy, the Governmentwishes pSPAs and cSACs included in a list sent to the European Commission, to beconsidered in the same way as if they had already been classified or designated. ListedRamsar sites, also as a matter of policy, should receive the same protection as designatedSPAs and SACs.

Sites of Special Scientific Interest (SSSIs)

7. Many SSSIs are also designated as sites of international importance and will be protectedaccordingly. Those that are not, or those features of SSSIs not covered by an internationaldesignation, should be given a high degree of protection under the planning system (seealso Part II of ODPM/Defra Circular ODPM 06/2005, Defra 01/2005) through appropriatepolicies in plans.

8. Where a proposed development on land within or outside a SSSI is likely to have an adverseeffect on an SSSI (either individually or in combination with other developments),planning permission should not normally be granted. Where an adverse effect on the site’snotified special interest features is likely, an exception should only be made where thebenefits of the development, at this site, clearly outweigh both the impacts that it is likely tohave on the features of the site that make it of special scientific interest and any broaderimpacts on the national network of SSSIs. Local authorities should use conditions and/orplanning obligations to mitigate the harmful aspects of the development and wherepossible, to ensure the conservation and enhancement of the site’s biodiversity orgeological interest.

PLANNING POLICY STATEMENT 9 | National Planning Policies6

Regional and Local Sites

9. Sites of regional and local biodiversity and geological interest, which include RegionallyImportant Geological Sites, Local Nature Reserves and Local Sites, have a fundamental role to play in meeting overall national biodiversity targets; contributing to the quality of life and the well-being of the community; and in supporting research and education.Criteria-based policies should be established in local development documents againstwhich proposals for any development on, or affecting, such sites will be judged. Thesepolicies should be distinguished from those applied to nationally important sites.

Ancient Woodland and Other Important Natural Habitats

10. Ancient woodland is a valuable biodiversity resource both for its diversity of species and forits longevity as woodland. Once lost it cannot be recreated. Local planning authoritiesshould identify any areas of ancient woodland in their areas that do not have statutoryprotection (e.g. as a SSSI). They should not grant planning permission for any developmentthat would result in its loss or deterioration unless the need for, and benefits of, thedevelopment in that location outweigh the loss of the woodland habitat. Aged or ‘veteran’trees found outside ancient woodland are also particularly valuable for biodiversity andtheir loss should be avoided. Planning authorities should encourage the conservation ofsuch trees as part of development proposals.

11. Through policies in plans, local authorities should also conserve other important naturalhabitat types that have been identified in the Countryside and Rights of Way Act 2000section 74 list, as being of principal importance for the conservation of biodiversity inEngland6 and identify opportunities to enhance and add to them.

Networks of Natural Habitats

12. Networks of natural habitats provide a valuable resource. They can link sites of biodiversityimportance and provide routes or stepping stones for the migration, dispersal and geneticexchange of species in the wider environment. Local authorities should aim to maintainnetworks by avoiding or repairing the fragmentation and isolation of natural habitatsthrough policies in plans. Such networks should be protected from development, and,where possible, strengthened by or integrated within it. This may be done as part of a widerstrategy for the protection and extension of open space and access routes such as canals andrivers, including those within urban areas.

6 List of habitats and species of principal importance for the conservation of biological diversity in England published by theSecretary of State for Environment, Food and Rural Affairs, in response to Section 74 (2) of the Countryside and Rights ofWay Act 2000. www.defra.gov.uk/wildlife-countryside/cl/habitats/habitats-list.pdf


Previously Developed Land

13. The re-use of previously developed land for new development makes a major contributionto sustainable development by reducing the amount of countryside and undeveloped landthat needs to be used. However, where such sites have significant biodiversity or geologicalinterest of recognised local importance, local planning authorities, together withdevelopers, should aim to retain this interest or incorporate it into any development of the site.

Biodiversity within Developments

14. Development proposals provide many opportunities for building-in beneficial biodiversityor geological features as part of good design. When considering proposals, local planningauthorities should maximise such opportunities in and around developments, usingplanning obligations where appropriate.

SPECIES PROTECTION

15. Many individual wildlife species receive statutory protection under a range of legislativeprovisions,7 and specific policies in respect of these species should not be included in localdevelopment documents (see also Part IV of ODPM/Defra Circular, ODPM 06/2005,Defra 01/2005).

16. Other species have been identified as requiring conservation action as species of principalimportance for the conservation of biodiversity in England.8 Local authorities should takemeasures to protect the habitats of these species from further decline through policies inlocal development documents. Planning authorities should ensure that these species areprotected from the adverse effects of development, where appropriate, by using planningconditions or obligations. Planning authorities should refuse permission where harm to thespecies or their habitats would result unless the need for, and benefits of, the developmentclearly outweigh that harm.

CANCELLATION OF POLICY

The following is hereby cancelled:

PPG9 “Nature Conservation” (1994)

7 Certain plant and animal species, including all wild birds, are protected under the Wildlife and Countryside Act 1981.European plant and animal species are protected under the Conservation (Natural Habitats, &c) Regulations 1994. Someother animals are protected under their own legislation, for example Protection of Badgers Act 1992.

8 Lists of habitats and species of principal importance for the conservation of biological diversity in England published by theSecretary of State for Environment, Food and Rural Affairs, in response to Section 74 (2) of the Countryside and Rights ofWay Act 2000 are available on the Defra website at www.defra.gov.uk/wildlife-countryside/cl/habitats/habitats-list.pdf

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Bat Conservation Trust

Bat SurveysGood Practice Guidelines

Derek Gardiner

Text Box

SDPNT PoE 2.7 – Bat Conservation Trust’s Survey Guidelines


Citation: Bat Conservation Trust (2007). Bat Surveys – Good Practice Guidelines.Bat Conservation Trust, London.

ISBN 978-1-872745-99-2

The guidelines described or referred to in this book do not necessarily reflect the policies of the BatConservation Trust or individuals and funding bodies involved in its production. No responsibility can be

accepted for any loss, damage or unsatisfactory results arising from the implementation of any of theactivities within this book. The use of proprietary and commercial trade names in this book does not

necessarily imply endorsement of the product by the authors or publishers.

© Bat Conservation Trust 2007

Front cover pictures: A Hopkirk, J Haddow, JJ Kaczanow, A Youngman and Surrey Bat Group.Designed by Matthew WardPrinted by Dexter Graphics

Printed on chlorine-free paper made of wood pulp from sustainable forests.

This publication has been sponsored by

Faber Maunsell is a leading supplier of multidisciplinary, environmental and engineering consultancy services in Europeand one of the largest suppliers of bat surveys in the UK. Faber Maunsell is committed to the highest standards inconsultancy and ecological practice and is proud to sponsor this important step forward in bat ecology and conservation.

The Institute of Ecology and Environmental Management represents and supports professionalecologists and environmental managers and seeks to raise standards within the profession. We welcomethese much needed guidelines as an important contribution to our aims. They will be of benefit to allwho have to plan, specify and assess bat surveys.


Bat SurveysGood Practice Guidelines

Editorial BoardChair: Katie ParsonsRichard Crompton

Richard GravesSteve MarkhamJean MatthewsMike Oxford

Peter ShepherdSandie Sowler

Bat Conservation Trust15 Cloisters House, 8 Battersea Park Road

London SW8 4BG, UK

Registered Charity No: 1012361 Company Limited by Guarantee. Registered in England No: 2712823. Vat Reg No: 877158773.

www.bats.org.uk

Bat Surveys – Good Practice Guidelines


Foreword 3Acknowledgements 4

Chapter 1 Introduction 5

1.1 Aim of this document 51.2 Who should use this document 51.3 Layout 51.4 Background 51.5 Context 6

1.5.1 Legislative context 61.5.2 Planning policy context 71.5.3 Biodiversity policy context 71.5.4 Other guidance 8

Chapter 2 Assessing the need for bat survey 9

2.1 What is a survey? 92.2 Reasons for surveying 9

2.2.1 Species conservation 92.2.2 Research 102.2.3 Planning for development 10

2.3 Assessing the need for surveys 122.3.1 Necessity of requesting a survey 12

Chapter 3 Preparation and planning 14

3.1 Introduction 143.2 Skills 143.3 Training 143.4 Licensing for bat survey 153.5 Health and safety 15

3.5.1 Health and safety policy 153.5.2 Hazards, risks and risk management 183.5.3 Health and safety training 18

3.6 Desk study 193.6.1 Information sources 193.6.2 Geographical extent of desk study 19

3.7 Site walkover survey 203.8 Selection of survey methods 21

3.8.1 Appropriateness of survey method 213.8.2 Cautionary note - non-invasive versus invasive techniques 233.8.3 Cautionary note - proving absence 233.8.4 Proportionality of survey 23

3.9 Survey timings 253.10 Recording and reporting surveys 273.11 Consultees 29

Chapter 4 Manual bat activity surveys 30

4.1 Introduction 304.1.1 Understanding bats’ use of the landscape 304.1.2 Aims of survey 344.1.3 Identifying bats by echolocation and flight 34

4.2 Equipment 354.3 Timing 374.4 Survey area 384.5 Survey effort and frequency 384.6 Methods 39

4.6.1 Walked transects 394.6.2 Driven transects 404.6.3 Boat transects 414.6.4 Backtracking to find roosts 414.6.5 Dusk emergence and dawn re-entry surveys 41

Chapter 5 Automated bat activity surveys 43

5.1 Introduction 435.2 Equipment 43

5.2.1 Bat detector recording systems 435.2.2 Automated activity logging systems 44

5.3 Timing, survey effort and frequency 445.4 Location of loggers and detectors 45

5.4.1 Automated detectors 455.4.2 Activity loggers 45

5.5 Sound analysis software 455.5.1 Analook 465.5.2 BatScan and BatSound 46

Chapter 6 Surveying buildings and built structures 47

6.1 Introduction 476.1.1 Understanding roosts and making an assessment of the likelihood of bats being present 476.1.2 Aims of survey 51

6.2 Methods 51

Contents

Contents

1 Bat Conservation Trust


Bat Conservation Trust 2

6.2.1 Approach to inspection surveys 516.2.2 Equipment 516.2.3 Searching buildings for bats 536.2.4 Searching bridges for bats 546.2.5 Dusk emergence, dawn re-entry and automated surveys of buildings and built structures 55

6.3 Timing 556.4 Survey effort and frequency 56

6.4.1 General points on survey effort 576.4.2 Internal and external inspection surveys 576.4.3 Dusk emergence, dawn re-entry and automated surveys 57

Chapter 7 Surveying underground sites 59

7.1 Introduction 597.2 Surveying underground sites for hibernacula 59

7.2.1 Understanding hibernacula and making an assessment of the likelihood of bats being present 597.2.2 Aims of survey 607.2.3 Methods 607.2.4 Timing and frequency 617.2.5 Equipment 61

7.3 Surveying underground sites for swarming activity 61

7.3.1 Understanding swarming sites 617.3.2 Aims of survey 627.3.3 Methods 627.3.4 Timing and frequency 627.3.5 Equipment 62

Chapter 8 Surveying trees 63

8.1 Introduction 638.2 Methods 64

8.2.1 Preliminary survey – all trees/woodlands 648.2.2 Assessing the value of trees affected by arboricultural works 65

8.2.3 Assessing the value of trees affected by woodland management or forestry works 668.2.4 Assessing the value of trees on development sites 668.2.5 Preliminary survey area coverage 668.2.6 Detailed survey 66

8.3 Timing 678.4 Frequency 688.5 Equipment 68

Chapter 9 Catching surveys 69

9.1 Introduction 699.2 Methods 699.3 Timing 709.4 Survey effort and frequency 709.5 Equipment 70

Chapter 10 Radio-tracking surveys 71

10.1 Introduction 7110.2 Methods 7110.3 Survey effort, timing and frequency 7210.4 Equipment 73

References 74

Appendix 1 Identification of bats by echolocation and flight 76

Appendix 2 Automated bat detector systems 80

Appendix 3 Glossary of bat terms 81

Appendix 4 List of abbreviations used 81

Appendix 5 Useful websites 82

Foreword


Foreword

The practical implementation of bat conservation is evolving rapidly. It is clear that, where development or landmanagement proposals have the potential to impact on bats, there needs to be quality control in the standard of batsurvey undertaken and that the survey should be appropriate to the situation.

Bat Surveys - Good Practice Guidelines provides a guide to the type and level of survey required for different habitats,in order to adequately ascertain their use by bats. These guidelines were developed with input from experts in the field.The Bat Conservation Trust (BCT) organised workshops and consultations to gather new knowledge and gainconsensus about survey methods and the effort required to have confidence in a survey’s results. These guidelinesprovide the best current thinking on bat surveys and future editions will be produced as knowledge about batsimproves and survey methods develop.

My thanks go to all who were involved with the production of this document. I hope that by bringing together theirexpertise, bats and the habitats they require will be better conserved now and in the future.

Dr Katie Parsons, Head of Biodiversity, BCT

Message from BCT’s Chief Executive OfficerThis document would not have been possible without the goodwill and enthusiasm of bat experts throughout the UKand Europe. I have enjoyed working with everyone to produce these guidelines and am confident that they form a firststep towards consistent, high quality bat surveys to benefit bat conservation.

Amy Coyte, BCT



AcknowledgementsThis publication has benefited greatly from the input of a large number of people. In particular, the Bat ConservationTrust would like to acknowledge the major contribution by Katie Parsons as an author and as Chair of the EditorialBoard. We would like to say a big thank you to other members of the Editorial Board, who were Richard Crompton,Richard Graves, Steve Markham, Jean Matthews, Mike Oxford, Peter Shepherd and Sandie Sowler. Each gavesignificant amounts of their time, free of charge, to pull the document together and drive it forward to completion.

We are grateful to Gail Armstrong, Dennis Blackwell, Conor Kelleher, Simon Mickleburgh, Kit Stoner and Linda Yostfor their editorial input and for proofreading.

We would like to thank the participants of two workshops on bat surveys that formed the basis of these guidelines –Jules Agate, Jim Alexander, Lothar Bach, Andrew Baker, Geoff Billington, Peter Boye, Patty Briggs, Robert Brinkman,Colin Catto, Amy Coyte, Richard Crompton, Ian Davidson-Watts, Johnny de Jong, Marcus Dietz, Matthew Dodds,John Drewett, Frank Greenaway, Tony Hutson, Gareth Jones, Conor Kelleher, Herman Limpens, Iain Mackie, TonyMartin, Jean Matthews, Brenda Mayle, Tony Mitchell-Jones, Martin Noble, Alison Rasey, Paola Reason, PhilRichardson, Mark Robinson, Tony Sangwine, Gillie Sargent, Peter Shepherd, Peter Smith, Kit Stoner, Stuart Wilsonand Stephanie Wray. BCT is grateful to Nigel Westerway Associates who facilitated the three-day workshop inDecember 2004 and to Baker Shepherd Gillespie and Cresswell Associates Ltd. who produced workshop reports.Many of these people also helped the sub-editors with the wording and content of specific chapters, as did AndrewCowan, John Drewett, Michael Ford, Alison Fure, Doug Ireland, Andy Kendall, Mark Robinson, Jon Russ, DavidWebb and SLR Consulting Ltd.

BCT would also like to thank all those who responded to the consultation held on the draft document betweenFebruary and March 2007. All comments and suggestions were considered by the Editorial Board and many wereincorporated into this version. Space precludes us from listing everyone here but their input was invaluable.

Several members of BCT staff have contributed a great deal to this document in a variety of ways: Michael Fray in handling the consultation responses as they came in; and Jules Agate, Jaime Eastham, Karen Haysom, SimonMickleburgh, Alison Rasey, Kit Stoner and Carol Williams in providing a sounding board and taking time to debatesections of the text and the use of terminology.

We would like to thank the following organisations for supporting the production of this document by fundingworkshops and the Head of Biodiversity’s time on this project: Environment Agency; Esmée Fairbairn Foundation;Forestry Commission; Highways Agency; and Natural England. Many thanks to Faber Maunsell for providing fundingtowards the printing costs, thereby enabling proceeds from the sale of this document to go towards bat conservation.

Many others have helped with the production of this document and it has not been possible to list everyone by name.We would like to thank you all for your time and expertise.

5

1.1 Aim of this documentTo conserve bats effectively, and to meet national andinternational statutory obligations and agreements, thereis a clear need for quality controls and appropriate levelsof bat survey to be established. To date, there has beenuncertainty around the type of survey and level of surveyeffort needed, when to survey, and how these decisionsare affected by the habitat, time of year, geographicallocation and the species present or likely to be present inthe prospective survey area.

This document provides good practice guidance for thosecommissioning, undertaking or reviewing bat surveysthroughout the UK. It is intended to bring aboutimprovements in the standard and consistency of batsurveys and survey reports and ultimately lead to greaterunderstanding about bats and improvements in theirprotection and conservation.

The guidance will need to be interpreted and adapted on acase-by-case basis, according to the expert judgement ofthose involved. There is no substitute for knowledge andexperience in survey planning, methodology andinterpretation of findings, and these guidelines intend tosupport these. Where examples are given they aredescriptive rather than prescriptive.

1.2 Who should use thisdocumentThe guidelines are for:

m ecologists (such as professional consultants)undertaking bat surveys;

m developers commissioning bat surveys fromprofessional consultants in order to provideinformation in support of a valid planningapplication;

m planners and ecologists working in local authorities,Statutory Nature Conservation Organisations(SNCOs) and non-governmental organisations whoare responsible for reviewing and assessing theimplications of bat survey results;

m nature conservationists with an interest in, andresponsibility for, the conservation of bats – for

example, bat workers undertaking voluntary roostvisits; and

m ecologists conducting ecological research into thebehaviour, occurrence and distribution of bats.

1.3 LayoutThe document starts by assessing the purpose of, andneed for, a bat survey. This is followed by preparation andplanning for surveys, and then by a chapter on each typeof survey. Additional information can be found in theAppendices.

This guidance will be most useful if read in its entiretyand then used as a reference to be ‘dipped’ into asrequired.

The document is available to purchase in hard copy;contact the Bat Conservation Trust for details. It is alsoavailable electronically to be downloaded from:www.bats.org.uk/biodiversity/BatSurveyGuidelines.asp

We intend to review and update this document as newinformation becomes available, so please check thewebsite regularly to ensure that you have the latestversion.

Case studies to illustrate the process of conducting batsurvey in different scenarios will be made available onthe website and periodically reviewed and updated.

1.4 Background The first draft of this document was prepared followinginput from UK and European bat experts via a series ofworkshops. Each chapter was then sub-edited by amember of the Editorial Board and a draft put out topublic consultation. Responses were received from a widevariety of end-users including ecological consultants,volunteer bat workers, local authority ecologists,developers, SNCOs and government departments.Following this consultation process, the Editorial Boardproduced the final document presented here.


Chapter 1

Introduction

1.5 Context1.5.1 Legislative contextAnnex II of the Council Directive 92/43/EEC 1992 on theConservation of Natural Habitats and of Wild Fauna andFlora (EC Habitats Directive) lists animal and plantspecies of Community interest, the conservation of whichrequires the designation of Special Areas of Conservation(SACs); Annex IV lists animal and plant species ofCommunity interest in need of strict protection. All batsare listed in Annex IV; some bats are listed in Annex II.

In the UK1, the EC Habitats Directive has been transposedinto national laws by means of the Conservation (NaturalHabitats, &c.) Regulations 1994 (as amended) and theConservation (Natural Habitats, etc.) Regulations(Northern Ireland) 1995 (as amended). These arecommonly and collectively known as the ‘HabitatsRegulations’. For the purposes of this document, wherereferred to in the text, they will be called the ‘HabitatsRegulations’. A summary of the relevant natureconservation legislation is shown in Box 1.1. Alwaysconsult the appropriate Habitats Regulations beforesurveying/ operating in each part of the UK and in otherEC member countries.

The Habitats Regulations transpose the EC HabitatsDirective to give bats, their breeding sites and restingplaces a high level of strict protection. In summary, it is acriminal offence (subject to certain specific exceptionsoutlined below) to:

m capture or kill a bat;m disturb a bat whilst in a place of shelter or rest; orm damage or destroy a bat’s breeding site or resting

place.

The breeding sites and resting places of bats are usuallyknown as ‘roosts’, of which there are a variety of types(see Chapter 6). Resting places also include, for example,feeding perches where a bat rests while waiting to catchor while consuming, prey. Bat roosts are protected evenwhen bats are not present.

No offence is committed if work is done under, and inaccordance with, a licence issued under the HabitatsRegulations. A licence may be issued for scientific oreducational purposes, conserving wild animals,preventing the spread of disease or another imperativereason of overriding public interest. The licensingauthority must be satisfied that there is no satisfactory

alternative to the proposed action and that it will not bedetrimental to the Favourable Conservation Status (FCS)of the bats.

Two main types of licences are of relevance to thisdocument:

1. Licences needed by trained bat surveyors orresearchers to allow them to undertake certainactivities or projects that would otherwisecontravene the Habitats Regulations; for example,entry into a bat roost or capture and radio-trackingof bats. These licences are dealt with in moredetail in Section 3.4.

2. Habitats Regulations licences (sometimes calledEuropean Protected Species (EPS) licences) permitwork that would otherwise constitute an offence bydisturbing bats and/or damaging or destroyingtheir roosts; this might include demolishing abuilding containing a bat roost, converting a barnor felling a tree. In each case the roost is eitherdestroyed or damaged. A Habitats Regulationslicence application consists of an application form,a Method Statement and a Reasoned Statement.



1 The Habitats Directive does not apply to the Isle of Man and the Channel Islands, which are part of the British Isles but not of the United Kingdom. Therelevant legislation in the Isle of Man and the Channel Islands should be consulted.

England and Wales

NorthernIreland

Scotland

Habitats Regulations (transposing the ECHabitats Directive)

Conservation (Natural Habitats, &c.)Regulations 1994 (Statutory Instrument (SI)1994 No. 2716) as amended by SI 1997 No.3055 and SI 2000 No. 192.

The Conservation (Natural Habitats, etc.)Regulations (Northern Ireland) 1995 (StatutoryRule (SR) 1995 No. 380) as amended by SR2004 No. 435.

Conservation (Natural Habitat &c) Regulations1994 as amended by SI 1997 No. 3055, SI2000 No. 192, Scottish Statutory Instrument(SSI) 2004 No. 475 and SSI 2007 No. 80.

Other nature conservation legislation

Wildlife and Countryside Act 1981 as amendedCountryside and Rights of Way Act 2000Natural Environment and Rural CommunitiesAct 2006

Wildlife (Northern Ireland) Order 1985 asamendedNature Conservation and Amenity Lands(Northern Ireland) Order 1985 as amendedEnvironment Order 2002

Wildlife and Countryside Act 1981 as amendedThe Nature Conservation (Scotland) Act 2004

Box 1.1 Summary of the main pieces of UK legislation pertaining to the protection of bats

The Method Statement is prepared by the ecologistand comprises survey information, assessment andmitigation/enhancement measures. These measuresare designed to establish that “the actionauthorised will not be detrimental to themaintenance of the population of the speciesconcerned at a favourable conservation status intheir natural range” (Habitats Regulations44(3)(6)).

1.5.2 Planning policy contextGovernment planning policy guidance throughout theUK2 requires local planning authorities to take account ofthe conservation of protected species when determiningplanning applications. This makes the presence of aprotected species a material consideration when assessinga development proposal that, if carried out, would belikely to result in harm to the species or its habitat.

In the case of European Protected Species such as bats,planning policy emphasises that strict statutory provisionsapply, to which a planning authority must have due regard(e.g. Habitats Regulations 3(4) and see also Section2.2.3).

For instance, “It is essential that the presence orotherwise of protected species, and the extent that theymay be affected by the proposed development, isestablished before the planning permission is granted,otherwise all relevant material considerations may nothave been addressed in making the decision (ODPMCircular 06/2005; paragraph 99)”.3

This requirement has important implications for batsurveys as it means that, where there is a reasonablelikelihood of the species being present and affected by thedevelopment, surveys should be carried out beforeplanning permission is considered.

The British Standards Institution has published a PubliclyAvailable Specification (PAS), PAS 2010 Planning to Haltthe Loss of Biodiversity: Biodiversity ConservationStandards for Planning in the UK - Code of Practice(British Standards Institution, 2006) as a code of practicefor planning authorities on how they should addressbiodiversity in their planning work. PAS 2010 identifies

where planning authorities have clear responsibilities forbiodiversity conservation. It specifies tasks that should beundertaken to discharge their planning functions in amanner that is compliant with statutory obligations,government policy and good practice. It provides aconsistent framework by which planning authorities cantake effective action to ensure, through forward planning,development control and management decisions, that theyare able to help halt the loss of biodiversity and thuscontribute to sustainable development.

1.5.3 Biodiversity policy contextBats were given legal protection in the UK because ofevidence that bat populations have declined significantlyin the last century. The Convention on BiologicalDiversity, signed in Rio de Janeiro, Brazil in 1992,requires Parties to develop national strategies and toundertake a range of actions aimed at maintaining orrestoring biodiversity. The UK Biodiversity Strategy wasproduced in response to the Convention.

Individual Species Action Plans (SAPs) have beendeveloped to address the causes of decline for thosespecies that have been identified as priorities for UKconservation action. Country-level lists contain speciesconsidered of national importance in biodiversitystrategies4. Local Biodiversity Action Plans (LBAPs) havebeen produced for additional species of local importance.Details of SAPs and LBAPs are available fromwww.ukbap.org.uk.

In England and Wales, the Natural Environment andRural Communities (NERC) Act, 2006 imposes a duty onall public bodies, including local authorities and statutorybodies, in exercising their functions, “to have due regard,so far as is consistent with the proper exercise of thosefunctions, to the purpose of conserving biodiversity”[Section 40 (1)]. It notes that “conserving biodiversityincludes restoring or enhancing a population or habitat”[Section 40 (3)].

In Scotland, the Nature Conservation (Scotland) Act 2004imposes a duty on every public body and office holder, inexercising any function, “to further the conservation ofbiodiversity so far as is consistent with the properexercise of those functions” [Section 1 (1)].

Introduction


2 Government policy guidance for biodiversity and nature conservationthroughout the UK is provided in the following planning documents:In England: Planning Policy Statement (PPS) 9 and ODPM Circular 06/2005.In Northern Ireland: Planning Policy Statement 2.In Wales: Technical Advice Note (TAN) 5.In Scotland: National Planning Policy Guidance (NPPG) 14 and PlanningAdvice Note (PAN) 60 PPS 2.

3 The principle of ensuring that the planning authority has sufficientinformation prior to determination has been established through judicialreview: ‘Cornwall Case’: R v Cornwall County Council ex parte Jill Hardy2001 Journal of Planning Law 786. Although this case strictly refers tostatutory EIA as planning permission was overturned in relation to the EIARegulations that require full environmental information to be presented, thishas been interpreted as applicable to all cases including assessments notsubject to the EIA Regulations.

4 The country-level biodiversity lists are found as follows: In England: The List of Habitats and Species Important to BiologicalDiversity in England was prepared under Section 74(2) of the Countrysideand Rights of Way Act 2000.In Northern Ireland: The List of Northern Ireland Priority Species wasprepared following a recommendation contained in the report Biodiversity inNorthern Ireland: Recommendations to Government for a BiodiversityStrategy by the Northern Ireland Biodiversity Group.In Scotland: The List of Species and Habitats Considered to be of PrincipalImportance for the Purpose of Biodiversity Conservation in Scotland wasprepared under Section 2(4) of the Nature Conservation (Scotland) Act 2004. In Wales: The List of Species of Principal Importance for the Conservationof Biological Diversity was prepared under Section 74 of the Countrysideand Rights of Way Act 2000.



1.5.4 Other guidanceEnglish Nature5’s Bat Mitigation Guidelines (Mitchell-Jones, 2004) focus on mitigation for bat roosts inbuildings, but also address a wide variety of topicsincluding legislation and licensing, and include a shortsection on survey objectives, methods and standards.

The third edition of the Bat Workers’ Manual (Mitchell-Jones and McLeish, 2004) covers all aspects of bat workand is an essential reference for anyone wishing to obtaina bat licence in the UK. Of particular interest to readersof these guidelines are Chapter 3, which contains anoverview of the types of methodologies that can be usedfor survey and monitoring for conservation purposes; andChapter 4, which gives detail on techniques for catchingbats.

For guidance on impact assessment see Guidelines forEcological Impact Assessment in the United Kingdom(Institute of Ecology and Environmental Management,

2006) and Guidelines for Baseline Ecological Assessment(Institute of Environmental Assessment, 1995, currentlyunder review).

Various guidance has been, and is being, produced by theScientific Working Group to The Agreement on theConservation of Populations of European Bats(EUROBATS). The UK Government is a Party to theAgreement, which was ratified in January 1994 followinga resolution adopted by the first Conference of Parties ofthe Convention on Migratory Species (CMS) to developan Agreement to protect all European bats. EUROBATSsets legal protection standards, while developing andpromoting trans-boundary conservation and managementstrategies, research, and public awareness across theAgreement area (48 Range States). Further informationabout the Agreement, along with adopted Resolutions andguidance can be found on the EUROBATS websitewww.eurobats.org. Particular Resolutions or guidancefrom EUROBATS are referenced in the appropriate placewithin this document.

5 English Nature joined with the Countryside Agency and the Rural Development Service to form Natural England on 2 October 2006. Any publicationspublished by English Nature before that date are attributed to English Nature, and afterwards to Natural England.

9

2.1 What is a survey?Surveying is a scientific activity during which peopleand/or equipment gather discrete information from a siteor area. Survey information should provide facts:objectives, methods, data (lists, tables, graphs, plans etc.),along with any limitations.

In these guidelines, a survey is defined as a samplingactivity that uses a wide range of variables to describe asite or an area, and is carried out as a time-bound once-only project, although the survey may involve repeatedvisits or observations. It is distinguishable frommonitoring, which involves repeated sampling, eitheryear-on-year or periodically, usually to assess whether aparticular objective or standard has been attained(definition adapted from www.jncc.gov.uk).

Bat surveys are undertaken for a variety of reasons. Themost basic type of survey will usually consist of thecollation of existing data and a walkover survey todetermine if there are any features or habitats that couldpotentially support bats. These basic surveys are oftenreferred to as scoping or first stage surveys (see Chapter3).

The objectives of a survey will influence the type ofsecond stage survey that is undertaken, the methods usedand the amount of survey effort needed (see Chapters 4-10).

Survey information should indicate:

m the species present or likely to be present at the siteor in the area;

m the approximate numbers of individuals and/or therelative importance of the population in a local,regional and national context; and

m when, and for what purposes, bats use the site.

2.2 Reasons for surveying Surveying for bats may be undertaken for a variety ofreasons but most will fall into one or more of thefollowing categories:

m Species conservation - where surveys may recordspecies occurrence, distribution and population size.

m Scientific research - where survey data can add tounderstanding of bat behaviour and/or can be used totest scientific hypotheses.

m Planning for development - where a surveyprovides adequate information to enable:

1. a planning authority to determine the effects ofdevelopment on bat species and to identify andstipulate any further information required onnecessary mitigation, compensation orenhancement measures; and/or

2. an informed decision to be taken as to whether aHabitats Regulations licence should be appliedfor; and/or

3. the relevant licensing body6 to determine anapplication for a Habitats Regulations licencethat would then enable the lawful disturbance ofbats or the damage/destruction of their roosts.

Each of these categories is dealt with in more detailbelow.

2.2.1 Species conservation Surveys may be required in order to inform and promotethe conservation of bats in a specified area. Protocols forconservation surveys are the same as for other types ofsurveys in the same environment (e.g. surveys ofbuildings, trees, underground sites and open spaces).


6 Habitats Regulations licences are issued in England, Wales and Scotland under Regulation 44(2)(e) and in Northern Ireland under Regulation 39(2)(e) of theappropriate legislation for the purpose of “preserving public health or public safety, or other imperative reasons of overriding public interest including thoseof a social or economic nature and beneficial consequences for the environment”. Habitats Regulations licences are issued by the following bodies:In England: Natural England.In Northern Ireland: Environment and Heritage Service, Department of Environment Northern Ireland.In Scotland: The Scottish Executive.In Wales : The Welsh Assembly Government.

Chapter 2

Assessing the need for bat survey



There are several types of survey that may be conductedfor species conservation according to the objectives.

a) Presence/absence

This type of survey would record which species arepresent in an area; for example, to produce a countyspecies atlas. Surveys should be designed to provide thenecessary level of confidence in a negative record.

b) Usage

This type of survey would identify the species that useparticular habitats or roost sites. This information couldbe used to inform conservation management andenhancement and/or to provide interpretation material forvisitors to a conservation site; for example, to identifypotential and actual tree roosts so that nature trails can bedesigned and located to avoid them. This would avoidconflict between the needs of bats and those of the publicin locations where trees may need to be managed (e.g.through tree surgery) to ensure public safety. Surveysshould be designed to provide the necessary evidence onwhich such decisions could be based.

c) Conservation management projects

A conservation licence issued by the relevant StatutoryNature Conservation Organisation (SNCO) is required forconservation projects that would otherwise constitute anoffence, such as grilling the entrances of mines and cavesor the alteration of roost sites. The proposed conservationactivity may lead to the disturbance of bats or the damageof a roost site but there will be a net conservation benefitto bats at the site. A comprehensive survey would berequired before a licence is issued and, as withdevelopment licences, a Method Statement detailing theproposed works and timetable would also be needed.

d) Surveys to inform potential site designation

A site being considered for statutory designation has tomeet specific criteria, such as those given in the Guidelinesfor the Selection of Biological SSSIs (Joint NatureConservation Committee, 1989). Survey work should bedesigned so as to provide the necessary information toestablish if those criteria are met. The aim of the survey isusually to provide evidence that the site is used by arequired number of bats in a given period of time.

Some Sites of Special Scientific Interest (SSSIs)designated because of bats consist of only a roost site(breeding roost or hibernaculum), but in some cases, key,non-roosting habitat has also been identified and includedwithin the designated area. This is perhaps most relevantfor sites that are also designated as Special Areas ofConservation (SACs), which can be protected for aspecies if the habitat “presents the physical or biologicalfactors essential to their life and reproduction” underArticle 4.1 of the Habitats Directive. Such factors includeforaging and commuting habitat that enable bats tosurvive in the landscape in addition to roosting places.

e) Projects on or adjacent to a Special Area of Conservation (SAC)

All plans for projects that may affect SACs must (underRegulation 48 of the Habitats Regulations 1994 [43 of theHabitats Regulations (Northern Ireland) 1995]) besubjected to a screening process in order to determine ifthe proposal, alone or in combination with otherproposals, will have a significant detrimental effect on theinterests for which the SAC is designated. Detailedguidance on this process can be found in the documentAssessment of Plans and Projects Significantly AffectingNatura 2000 Sites – Methodological Guidance on theProvisions of Article 6 (3) and (4) of the HabitatsDirective (European Commission, 2001).

2.2.2 ResearchSurveying for scientific research focuses onunderstanding bat lifestyles and behaviour. Studies areusually based on the testing of a hypothesis and the needto obtain objective evidence in support of it. The resultsand conclusions of such research can be important forconservation if they increase our ecological knowledgeand lead to better informed conservation managementdecisions and the development of more effectivemitigation. This in turn drives improvements in surveymethods that surveyors concerned with conservation anddevelopment should adopt.

2.2.3 Planning for development For development proposals requiring planningpermission, the presence of bats, and therefore the needfor a bat survey, is an important ‘material planningconsideration’7. Adequate surveys are therefore requiredto establish the presence or absence of bats, to enable a prediction of the likely impact of the proposeddevelopment on them and their breeding sites or restingplaces and, if necessary, to design mitigation andcompensation. Similarly, adequate survey informationmust accompany an application for a HabitatsRegulations licence required to ensure that a proposeddevelopment is able to proceed lawfully.

The term ‘development’ used in these guidelines includesall activities requiring consent under relevant planninglegislation and/or demolition operations requiringbuilding control approval under the Building Act 19848.

English Nature states that development in relation to bats“covers a wide range of operations that have thepotential to impact negatively on bats and batpopulations. Typical examples would be the construction,modification, restoration or conversion of buildings andstructures, as well as infrastructure, landfill or mineralextraction projects and demolition operations.”(Mitchell-Jones, 2004).

7 For instance – see paragraph 98 of ODPM Circular 06/2005 Biodiversityand Geological Conservation – Statutory Obligations and their Impactwithin the Planning System.

8 The Building Act 1984 is UK statute and is the enabling Act of the

Building Regulations (as amended) in England and Wales. In Scotland, theBuilding (Scotland) Act 2003 is implemented by the Building (Scotland)Regulations 2004. In Northern Ireland, the Building Regulations (NorthernIreland) Order 1979 (as amended) is implemented by the BuildingRegulations (Northern Ireland) 2000 (as amended).


11

When considering development, competent authoritiesthroughout the UK must have regard to the safeguardingof European Protected Species. Regulation 3(4) of theHabitats Regulations 1994 [also 3(4) in the HabitatsRegulations (Northern Ireland) 1995] states: “Withoutprejudice to the preceding provisions, every competentauthority in the exercise of their functions, shall haveregard to the requirements of the Habitats Directive so faras they may be affected by the exercise of their functions.”

This means that planning authorities must apply threetests when determining planning applications whereEuropean Protected Species may be involved. These testsmean they must have “due regard” to:

m the purpose of preserving public health or publicsafety or other imperative reasons of overridingpublic interest including those of a social oreconomic nature and beneficial consequences ofprimary importance for the environment - Regulation44(2)(e) in the Habitats Regulations 1994 [39(2)(e)in the Habitats Regulations (Northern Ireland) 1995].

As long as:

m there is no satisfactory alternative – Regulation44(3)(a) [39(3)(a)]; and

m the action authorised will not be detrimental to themaintenance of the species concerned at aFavourable Conservation Status in their natural range– Regulation 44(3)(b) [39(3)(b)].

These survey guidelines should therefore be used toinform surveys that are part of an application submittedfor approval to a competent authority responsible forcontrol and management of new development through theplanning process.

Planning case law has established9 that “It is essentialthat the presence or otherwise of protected species, andthe extent that they may be affected by the proposeddevelopment, is established before the planningpermission is granted, otherwise all relevant materialconsiderations may not have been addressed in makingthe decision10”. Surveys should be carried out beforeplanning permission is considered; only in exceptionalcircumstances should they be carried out after consentthrough planning conditions.

It is in the interests of all developers to ensure thatsufficient information is submitted with a planningapplication to enable the competent planning authority to

determine the application efficiently, lawfully and in atimely fashion. Survey data accompanying a planningapplication must be as up-to-date as possible. It is likelythat the survey will provide only one part of theinformation that will need to be submitted. A full reportwill also include details of the proposed activity, anassessment of potential impacts and an avoidance,mitigation and compensation strategy11 to deal withpredicted adverse effects.

The presence of bats very rarely precludes developmentbut planning conditions and obligations may be used tolimit the extent of disturbance or restrict the timing ofdevelopment activities. These may also stipulatemitigation, compensation and/or enhancement measures.Alternatively, or in addition, this may be achievedthrough the issue of a Habitats Regulations licence.

Government policy encourages developers to enter intopre-application discussions in order to seek advice on theinformation to be submitted with a planning application.Where bats are likely to be present (see Box 2.1),developers and consultants would be well advised toapproach the planning authority at an early stage todiscuss the need for a bat survey.

The implications of not carrying out an appropriatesurvey at a site that subsequently proves to have roostingbats can be significant. Insufficient information onprotected species can render an application invalid(meaning that it will not be registered or determined) orlead to refusal or deferral of planning permission,resulting in significant delays and additional costs andmay ultimately lead to a criminal prosecution if bats areharmed or their roosts destroyed.

Where a site has been designated as a Special Area ofConservation (SAC) because of its bat interest, theplanning authority must “make an appropriate assessmentof the implications for the site in view of the site’sconservation objectives” - Regulation 48(1) [43(1)]before granting planning permission. It can only grantconsent after it has ascertained that the proposal “will notadversely affect the integrity of the European site” -Regulation 48(5) [43(5)].

The guidelines may also enable Building ControlOfficers, in their role as a competent authority, to haveregard to the Habitats Regulations12 in relation to theirfunctions under the Building Act 1984 where they areresponsible for control and management of demolitionoperations13 through the building control process.


9 Regina vs. The Cornwall County Council ex parte Hardy 2001 Journal ofPlanning Law 786.

10 This requirement has been strongly emphasised in government planningpolicy e.g. paragraph 99; ODPM Circular 06/2005 and in the ConsultationDraft of Welsh Planning Technical Advice Note (TAN) 5 (20056).

11 A mitigation strategy should provide an assessment of the effects of theproposal and the options for avoiding, or reducing to an acceptable level, anynegative impacts. Where it is not possible to avoid or reduce the effects of animpact to an acceptable level, the residual adverse impact may requirecompensatory measures to be implemented. This is usually written in theform of a Method Statement. Mitigation proposals are not dealt withspecifically in these guidelines, but further information can be found in theBat Mitigation Guidelines (Mitchell-Jones, 2004).

12 Where a Section 80 Notice (in England and Wales) has been served forthe proposed demolition of a building, the presence of bats may be animportant material consideration when a local authority’s Building ControlSection considers serving a Counter Notice (a Section 81 notice), setting outconditions that must be complied with during the course of demolition. InScotland a building warrant is required for demolition (and all building workto which the Building (Scotland) Regulations 2004 apply).

13 When the owner of a building over 50m3 intends to have it demolished,the legal requirements of Sections 80-83 of the Building Act 1984 impose arequirement for formal notification to be given to the local authority at leastsix weeks before any demolition work starts. This is to enable all appropriatepeople and organisations to be advised of the proposed demolition and toensure that measures to protect the public and/or to preserve public amenitiesare put in place.



2.3 Assessing the needfor surveys Every survey has a cost in time or money or both. It istherefore very important that the following are consideredat the outset:

m that it is reasonable to request a survey; m that the method (or suite of methods) is appropriate

to meet the objectives of the survey; andm that the survey effort is proportionate to the context

and appropriate for the purpose of the survey.

The necessity of requesting a survey is considered inmore detail below. Once it has been agreed that a surveyis necessary, the appropriate methods and level of surveyeffort to employ must be decided during the preparationand planning process (see Section 3.8).

2.3.1 Necessity of requesting asurveyIt is not necessary to have a record of bats at a locationfor a survey to be required. In practice, the locations ofonly a small minority of bat roosts have been formallyrecorded and even householders with large roosts of batsoccupying their property may be unaware of theirpresence. Ephemeral (transitory) roosts such as those intrees are particularly difficult to detect.

The decision to undertake a bat survey must be based ona reasonable likelihood that bats may be present in thestructure, tree, feature, site or area under consideration.

With regard to development, the government has statedthat “bearing in mind the delay and cost that may be

involved, developers should not be required to undertakesurveys for protected species unless there is a reasonablelikelihood of the species being present and affected by thedevelopment14”.

The trigger list in Box 2.1 gives common developmentsituations where bats are likely to be encountered andtherefore where it is most likely that a bat survey andassessment will need to be undertaken. It should be notedthat the trigger list is a guide but it is by no meansexhaustive. For example, seemingly unlikely habitats withfew visible features for bats might provide good habitat atparticular times of year. An example is moorland that hasbeen found to have increased bat feeding activity duringthe heather flowering season.

Box 2.1 has been prepared in conjunction with theAssociation of Local Government Ecologists (ALGE),which in turn has been working with the Department ofEnvironment, Food and Rural Affairs (Defra) and NaturalEngland to prepare illustrative guidance15 for localplanning authorities, indicating when it is reasonable forsurveys for protected species to be undertaken bydevelopers. This is to ensure that the planning authorityreceives sufficient information with a planningapplication. During the scoping exercise that follows theearly stages of a bat survey (desk study and walkover -see Sections 3.6 and 3.7), an assessment will be made ofthe types and levels of further survey, if any, that areappropriate and proportionate (see Section 3.8).

Development is recognised as having one of the mostsignificant impacts on bats. The necessity of requiringsurveys for other activities - such as forestry - is dealtwith in other chapters - see, for example, Chapter 8.

The trigger list in Box 2.1 might also assist researchersand conservationists in focusing and prioritising theirsurvey effort at particular sites or habitats with the mostlikelihood of finding bats.

14 Paragraph 99 ODPM Circular 06/2005 Biodiversity and GeologicalConservation – Statutory Obligations and their Impact within the PlanningSystem.

15 Validation Checklists and Guidance Notes: Template for Biodiversity andGeological Conservation (Association of Local Government Ecologists andothers, in preparation). This is intended to act as a template for planningauthorities who are encouraged to refine their own local requirements basedon local knowledge and evidence about where bats are most commonlyencountered within their area. Developers seeking advice on when a batsurvey may reasonably be required should therefore also refer to any localprotected species survey requirements specified by the relevant planningauthority.


13

Notes

1 Bats may be found in other situations beyondthose listed in Box 2.1. For example, pipistrellebats will occupy modern buildings and builtstructures (see Chapter 6). Developers, and thoseacting for them, should be mindful that disturbanceof any roosts or harm to a bat or bats is a criminaloffence (see Section 1.5.1).

2 The trigger list in Box 2.1 is based on work doneby the Durham Bat Group and Durham CountyCouncil and by the Surrey Bat Group and SurreyCounty Council. The criteria also draw on the BatMitigation Guidelines (Mitchell-Jones, 2004).

3 The trigger list in Box 2.1 will be particularlyuseful in signalling a bat survey in situationswhere a population of a species might be presentand an action would consequently be detrimentalto the maintenance of a population of a species at aFavourable Conservation Status and thereforewould be contrary to the statutory requirements ofRegulation 44(3)(b) of the Habitats Regulations1994 [39(3)(b)] (see Section 2.2.3).

4 Where bat roosts are of international importance,they may have been designated as Special Areas ofConservation (SACs). There are cases where largerscale developments 5-10 km away from such siteshave been required to undertake bat surveys andimpact assessments in order to account forforaging bats using extensive areas around theirroost.


Trigger list of where bats are likely to be present and where developers can reasonably be expected tosubmit a bat survey.

(i) Proposed development which includes the modification, conversion, demolition or removal of buildingsand structures (especially roof voids) involving the following: m all agricultural buildings (e.g. farmhouses and barns) particularly of traditional brick or stone

construction and/or with exposed wooden beams greater than 20 cm thick; m all buildings with weather boarding and/or hanging tiles that are within 200 m of woodland and/or

water;m pre-1960 detached buildings and structures within 200 m of woodland and/or water; m pre-1914 buildings within 400 m of woodland and/or water;m pre-1914 buildings with gable ends or slate roofs, regardless of location;m all tunnels, mines, kilns, ice-houses, adits, military fortifications, air raid shelters, cellars and similar

underground ducts and structures; m all bridge structures, aqueducts and viaducts (especially over water and wet ground); andm all developments affecting buildings, structures, trees or other features where bats are known to be

present.

(ii) Proposals involving lighting of churches and listed buildings or floodlighting of green space within 50 mof woodland, water, field hedgerows or lines of trees with obvious connectivity to woodland or water.

(iii) Proposals affecting quarries with cliff faces with crevices, caves or swallets.

(iv) Proposals affecting or within 400 m of rivers, streams, canals, lakes, or within 200 m of ponds and otheraquatic habitats.

(v) Proposals affecting woodland or field hedgerows and/or lines of trees with obvious connectivity towoodland or water bodies.

(vi) Proposed tree work (felling or lopping) and/or development affecting:m old and veteran trees that are older than 100 years; m trees with obvious holes, cracks or cavities; andm trees with a girth greater than 1 m at chest height.

(vii) Proposed development affecting any feature or locations where bats are confirmed as being present,revealed by either a data trawl (for instance of the local biological records centre) or as notified to thedeveloper by any competent authority (e.g. planning authority, Statutory Nature ConservationOrganisation or other environmental or conservation organisation).

Box 2.1 Likelihood of bat presence – planning and development trigger list for bat surveys



3.1 IntroductionOnce it has been decided that a survey is required,preparation and planning will be needed. This chapterprovides guidance on this process and covers the skillsand experience necessary, licensing and health and safetyrequirements, preliminary data gathering by desk studyand site walkover, the selection of appropriate methodsand timings for further survey, and planning for thereporting and recording of surveys.

3.2 Skills Surveying for bats is a highly skilled task requiringtraining and should only be carried out by those withrelevant experience. Anyone commissioning surveys orreviewing them should be sure that the surveyor has thenecessary expertise. It is the duty of all surveyors toensure that they are experienced in, and trained for, thework that they are undertaking. Surveyors should beaware of their own limitations in terms of knowledge andexperience; for example, many bat workers outside Walesand south-west England will have little or no experienceof working with horseshoe bats. This should be taken intoaccount if asked to undertake work in these parts of theUK.

While membership of a professional institute such as theInstitute of Ecology and Environmental Management(IEEM) or a Chartered Environmentalist (CEnv)qualification does not test a skill level with respect to batsor other species, the conditions of membership do requiremembers to undertake surveys in a professional mannerand make clear any limitations to their work. Currently inthe UK, there is no agreed standard for bat survey workto which ecologists or zoologists should operate, and nospecific qualification that should be gained. The BatConservation Trust is in the process of developingstandards in bat training which will outline the knowledgeand skills required for proficiency in different tasksrelating to bat work.

The Statutory Nature Conservation Organisations(SNCOs) license bat workers for conservation, science oreducation. Potential workers must undergo training andpeer review before being licensed as a bat worker. Thepossession of such a licence is an indication that thesurveyor has reached a minimum standard of training,although this may not relate to survey work, impactassessment or the design and implementation of

mitigation schemes. It is reasonable for those hiring batconsultants to ask for evidence of previous work, in orderto demonstrate the surveyor’s competence in the type ofwork they are being requested to undertake. By the same token, those surveying and reporting on surveys,especially unlicensed bat workers, should includeevidence of their competence in the documents theyproduce.

Basic skills needed for bat surveying can often be gainedinitially through membership of a local bat group or fromattendance at a bat foundation course where a basicknowledge of bat biology and behaviour is acquired.Thereafter, attributes required include a good ear to heardifferences in sounds produced through heterodyne batdetectors, sharp eyesight to find droppings, urine stainingetc., good vision in poor light levels, agility to gain accessto potential bat roosting sites and stamina to remainawake and alert during late night or early morning surveysessions! Not only is it important to know what to lookfor but also where to look for it, as this in itself can bediagnostic of the species present. Key skills to beacquired are an understanding of building, barn, bridgeand tree structure and terminology, and field signsincluding bat remains, droppings and their identification.Also, a thorough knowledge of species ecology, withparticular reference to roosting ecology and thereforelikely location of bats (especially when out of sight), andappropriate mitigation is also required.

3.3 Training A thorough knowledge of bat biology, including keepingabreast of latest research findings, is necessary in order toundertake surveys and interpret the findings; to do this,regular formal or informal training is necessary.

Training in bat surveying can be sourced in a number ofways. Many consultants learn in-house through mentoringand/or attending a variety of training courses offered by anumber of individuals and organisations, including the BatConservation Trust (BCT). These range from courses onbasic surveys using bat detectors to more specialisedcourses on particular aspects of survey, for example,surveying buildings, barns or trees. Other courses that maybe of relevance include those on planning for protectedspecies. Some bat groups may allow consultants to gainexperience with them, especially if voluntary commitmentis made to the group in return. BCT’s National BatConference aims to update bat workers with the latestresearch findings through its speakers and workshops.

Chapter 3

Preparation and planning


15

For further information about training courses offered bythe BCT, request a current training brochure from theBCT National Bat Helpline (0845 1300 228) or downloada copy from the website www.bats.org.uk.

3.4 Licensing for batsurveyThis section provides a brief overview of the system forlicensing bat surveyors. For detailed information, therelevant licensing body and its guidance should beconsulted (see also Section 1.5.1).

A surveyor may need to undertake activities duringsurvey work that would violate the strict protectionafforded to bats by the Habitats Regulations. A licence isrequired to permit such activities, for example, entry intoa bat roost and temporary disturbance of bats during thesurvey or capture and marking with radio-transmitters.

These licences are varyingly referred to as SNCO batlicences, science/education licences, survey licences orconservation licences. These titles are reflective of thepurposes for which they are granted under the HabitatsRegulations and the fact that the SNCOs regulate theissue of such licences (see also Section 1.5.1). These arepersonal licences allowing a surveyor to disturb, handleor mark bats, or to improve their roost sites where themain purpose of the work is for conservation of thespecies at that site. They do not cover work such asdestruction of a roost site for purposes of development,overriding public interest or public health and safety,which would be covered by a Habitats Regulationslicence (see also Sections 1.5.1 and 2.2).

It is best practice for surveys of potential roosts to bedone by licensed surveyors because if a roost isdiscovered and needs to be entered, an SNCO licence isrequired as bats may be deliberately disturbed. Ondiscovering a roost in a previously unknown location, anunlicensed bat worker must withdraw.

Only an SNCO licensed bat worker can enter a knownroost or area occupied by bats. However, it is not alwaysnecessary for surveyors to have an SNCO bat licence. Forexample, a licence is not needed for undertaking activitysurveys using bat detectors in the field or emergencesurveys outside roosts as these do not cause disturbanceto bats when undertaken properly.

Licences for more invasive survey methods, such as mistnetting, marking and radio-tracking, are usually issued forspecific projects requiring their use. The licences areissued for a set period of time, at a particular location andfor a given number of animals. The applicant will need todemonstrate that the level of disturbance is justified andthat they have the necessary experience and training toundertake the work.

3.5 Health and safety Health and safety is an important issue for anyoneorganising a bat survey whether for development,research, conservation or enjoyment.

Bat surveys can be difficult, involve challenginglocations, unsociable working hours, extensive travel,disrupted sleep and many potential hazards. It isimportant that these risks are adequately considered andaccounted for during the planning of each survey. Whilebat conservation is important, it should be rememberedthat the most important mammals on any survey are thesurveyors.

3.5.1 Health and safety policyIt is the legal duty of an employer to have a health andsafety policy. Section 2(3) of the Health and Safety atWork etc. Act 1974 (HSW Act) states: “Except in suchcases as may be prescribed, it shall be the duty of everyemployer to prepare and as often as it may be appropriaterevise a written statement of his general policy withrespect to the health and safety at work of his employeesand the organisation and arrangements for the time beingin force for carrying out that policy, and to bring thestatement and any revisions of it to the notice of all hisemployees”.

While employers with fewer than five employees are notrequired to have a written health and safety policy, theyare still liable for their health and safety and shouldconsider it best practice to have and uphold such a policy.

The Working at Height Regulations 2005 cover allinstances where a task involves working at height andthere is a risk of falling. Although the obvious scenariosfor working at height during bat surveys include work inbuildings, on structures such as bridges and in trees,working at height may also arise while surveyingunderground or on quarry faces. The Working at HeightRegulations 2005 make particular reference to the use andlimitations of ladders as a means of access. For furtherinformation, these and other Regulations can bedownloaded from the Office of Public Sector Informationwebsite www.opsi.gov.uk

Due to the unsociable hours often inherent in bat work,surveyor tiredness is a very real risk. The Working TimeRegulations 1998 (as amended) advise a “rest period ofnot less than eleven consecutive hours in each 24-hourperiod”.

Where relevant health and safety regulations andguidance exist, it is good practice to adhere to them.Guidance on safety and risk management-related issuescan be found on the Health and Safety Executive’swebsite (www.hse.gov.uk) or by calling the HSE Infoline(0845 345 0055).




Types of hazards and risksassociated with fieldwork

Lone working

Tirednessa, b, c, d

Bad weathera, c

Work in the darka, b, d

Work in confined spacesb, d

Work underground wherethere may be sudden drops,changes in roof height,unstable rock or decayingfixturesd

Work at height e.g. inatticsb, treesc or on quarryfaces where there is a riskof fallingd

Busy roads, on railways oron farmland with workingagricultural machinerya, b

Derelict structures/construction sitesb/treesc

where there is risk of fallingmasonry or tree branches

Water (rivers, streams,ditches, lakes, canals etc.)a

Unfenced slurry or silagepits, ponds, grain silos andstoresa

Procedures to remove or reduce risk posed by thehazard

Lone working should be avoided wherever possible. If it is unavoidable, a buddy system and lateworking procedure should be put in place. It isparticularly important for a second person to bepresent when working at height. Always park your car so that you can drive straightaway rather than have to do a three-point turn.This is useful in case of emergencies but also incases of aggression.

Limits to the number of surveys being carried outare recommended:• Staff doing bat surveys only (with no daytime

work) – up to four dusk or four dawn or two ofeach or two all-nights per week.

• Staff doing other work – up to two dusk or twodawn or one of each per week. All-night surveysare not appropriate.

Awareness of the weather forecast.

Confined spaces training – see Section 3.5.3.

Mine safety training – see Section 3.5.3.

Arboricultural climbing training – see Section 3.5.3

Employ safe methods of crossing watercourses suchas rivers, streams and ditches. Check the floodconditions.

Take care in vicinity of such areas.

Equipment to remove orreduce risk posed by thehazard

In case of separation oraccident a mobile phone (orsatellite phone in remoteareas), two-way radio, whistle,map and compass should becarried.

All-weather clothingappropriate to the localsituation (fieldwork in the northof Scotland will require agreater level of protection thanin the south of England at thesame time of year).

Powerful torch (with sparetorch, batteries and bulbs).

Protective warm clothing,strong boots, helmet andhelmet-mounted lamp. Laddersand/or ropes if necessary forthe site.

Safe means of access e.g.ladders, platforms and ropes.

Fluorescent jacket (appropriateto road type).

Hard hat, fluorescent jacket,safety footwear.

Life jacket (consider self-inflating type to allow forgreater mobility).

Table 3.1 Hazards and risks associated with fieldwork and procedures and equipment used in management of those risks. Risks particularly associated with manual bat activity surveys in the fielda, with roost surveys of buildingsb, treesc andunderground sitesd are marked accordingly.



Slips, trips and falls causedby rough grounda, b, c, d

Sunburn/sunstroke

Diseases such as Weil’sdisease, Lyme disease,ornithosis (an infectiousdisease that affects birdsand can affect humans andother mammals) andtetanus (for example, fromrusty barbed wire)

Insect bites and stings(horseflies, ticks, etc.)

Bat biteb and rabies(European Bat Lyssavirus)

Asbestos, fibreglass and dustb

Sharp objects, such asbroken glass or hypodermicsyringesa, b

Land that has been sprayeda

Aggressive farm animalssuch as guard dogs, geese,bulls and cows with calvesat foota, b

Shooting/predator control(often takes place at dusk)a

Verbal and physical assaulta

Take care in moving around, ensure visibility isadequate.

Use sunscreen, hat, long-sleeved shirt.

Awareness of diseases e.g. carrying a Weil’s diseaseawareness medical card or being familiar with tickidentification.

All those who handle bats should be vaccinatedagainst rabies because of the risk of European BatLyssavirus. Care should be taken when handling bats to avoidgetting bitten. Information and advice on vaccinations for batworkers and what to do in the event of a bat bitecan be obtained from the Health ProtectionAgency’s website (www.hpa.org.uk) or by callingthe HPA Centre for Infections (020 8200 4400).Further information on vaccination is available inthe Department of Health ‘Green Book’Immunisation Against Infectious Disease 2006which can be obtained from the Department ofHealth’s website (www.dh.gov.uk/en/Policyandguidance/Healthandsocialcaretopics/Greenbook/index.htm).

Every non-residential building should have anAsbestos Register. Ask to see it for the building tobe surveyed, particularly those built between 1950and 1985. Asbestos should be avoided andspecialists called. See Section 3.5.3 for details of asbestos training.

Check with landowners/agents to establish whetherpesticides have recently been used on land beingaccessed. Many pesticides have a ‘harvest interval’between spraying and harvesting and this is alsothe period when people should not enter the land.

Check with landowners/agents to establish thelocations of livestock, guard dogs, geese, etc.

Check with landowners/agents whether anypredator control is likely to be taking place.

Avoid lone working, work within sight ofaccompanying surveyor, park so as to be able toleave quickly.

Protective clothing with anyopen cuts covered.

Ornithosis – protective dustmask and gloves.

Insect repellent.

Appropriate gloves should beworn when handling bats(advice is available from theBat Conservation Trust).

Asbestos - disposable overallsand respirator.Fibreglass and dust – protectivedust masks (conforming to BSEN149), safety glasses andoveralls.

Safety work boots withprotective toecaps andreinforced soles, impact gradegloves, overalls, first aid kit.

Attack alarm.



3.5.2 Hazards, risks and riskmanagementAll jobs carry risks. Bat surveying and fieldwork havesome very specific risks from particular hazards. Ahazard has the potential to cause harm; it is associatedwith degrees of danger and is quantifiable. Risk is thelikelihood of harm from a particular hazard and itsseverity i.e. risk = severity x likelihood. If the risk is toohigh the action should not be undertaken.

The simplest way to ensure protection from harm is toremove the hazard or the risk that the hazard poses. Usecommon sense – if it seems dangerous, do not do it unlessyou can make it safe first! No activity should beattempted without undertaking measures to bring thelikelihood of risk within acceptable limits. Many of therisks associated with bat survey and fieldwork can beavoided, removed or reduced by employing measures putin place as a result of thorough risk assessment. Table 3.1lists risks associated with bat fieldwork and measures thatcan be taken or equipment that can be used to managethat risk.

There are cases of surveyors/handlers suffering veryserious consequences from their work. Examples include:

m a bat surveyor/handler who died as a result of beingbitten by a bat suffering from European BatLyssavirus 2;

m a surveyor shot in the chest by a gamekeeper whowas ‘lamping’ foxes;

m surveyors attacked and their equipment stolen whileundertaking a bat survey on the edge of an urbanarea; and

m car accidents in which a contributory factor mayhave been excessive tiredness following night-timesurveys.

A risk assessment may take many forms but it isprincipally a list of identified potential site-specifichazards and the means used to reduce or remove them.Relevant facts should be formally set down in a riskassessment form which complies with legal requirementsas well as being best practice.

A risk assessment should be prepared and completed forevery job undertaken. Targeted risk assessments will berequired for every site, to ensure risks in addition to thoselisted in Table 3.1 are taken into account. On arrival onsite, the risk assessment should be reviewed to establishthat all possible risks have been taken into account.

Guidance on risk assessments for bat and other surveywork is available from various sources including the BatWorkers’ Manual (Mitchell-Jones and McLeish, 2004),the Institute of Ecology and Environmental Management(available only to members), and from sample riskassessments, for example, from volunteer schemes suchas the BCT’s National Bat Monitoring Programme.

In some complex situations, such as where a building isunsafe and asbestos may be present, a Method Statementmay also be needed.

As most bat survey work involves at least one, or acombination of several, risk factors it will seldom beappropriate for one person to undertake a survey unlessaccompanied on site.

All equipment used should be regularly checked andmaintained, in line with appropriate legislation.

3.5.3 Health and safety trainingTraining courses are available for those likely to visithigh-risk sites or to undertake high-risk activities duringsurveys. High-risk sites include:

m construction sites;m roads;m railways;m enclosed spaces;m caves, quarries and mines;m derelict buildings;m buildings and structures which contain asbestos;m water bodies;m treatment works;m industrial plants;m remote locations; andm sites with criminal activities and/or hostile local

residents.

The following locations require advanced knowledge andthe use of specialist equipment, practice in the use ofwhich can be gained on the specialist training coursesindicated:

m work in confined spaces (tunnels, culverts etc.) -Confined Spaces training course;

m work in trees - Arboricultural Climbing course withspecialist equipment;

m work underground (mines, caves etc.) - ConfinedSpaces training course or Mine Safety course. Basiccaver training and advice on safety issues in specificlocal caves and mines can be obtained via the BritishCaving Association (BCA), Regional CavingCouncils or local caving clubs.

Following a number of fatalities, the Health and SafetyExecutive has introduced a certification scheme for allthose who need to work on active construction sites. Acourse is available from the Construction IndustriesTraining Board (CITB) to obtain a Construction SiteCertification Scheme (CSCS) card. These are now oftenrequested before entering a construction site.

It is advisable to consider attending an AsbestosAwareness training course if entering buildings withasbestos could become a part of survey work.


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3.6 Desk studyA desk study or data trawl should always be conducted atan early stage when planning bat surveys. It is aprerequisite to deciding the type and intensity of furthersurvey where required. However, it is unlikely that a deskstudy alone would ever provide enough information tofully assess the value of an area for bats; an initial visit tothe site for a walkover or scoping survey is recommended(see Section 3.7). Together, the desk study and walkoversurvey should inform the scoping exercise that determineswhat further survey work is required (see Section 3.8).

3.6.1 Information sourcesThe first step in any data trawl exercise should be toobtain maps of the area. These can be supplemented withaerial images, which may be obtained from sources suchas Google Earth (www.earth.google.com) and Multimap(www.multimap.com). From such maps, an experiencedsurveyor can gain an impression of the habitats andfeatures likely to be important for bats and make ajudgement of the species likely to be present anddetermine where best to look for them.

Distribution atlases, such as the Distribution Atlas of Batsin Britain and Ireland (Richardson, 2000), should beconsulted. Local distribution atlases should also beconsulted where available. The date of publication ofsuch sources should be borne in mind; more recentrecords may exist but not be represented.

Online sources of distribution data include the NationalBiodiversity Network (www.searchnbn.net); however,the likelihood is that not all records exist on suchdatabases and not all parts of the UK have been surveyedso the data coverage may be patchy. The absence of aspecies record in an area does not necessarily mean thatthe species is not there.

It is important to obtain known information about batroost sites or any sites of nature conservation importancedesignated for their bat interest near to, or on, the site inquestion. When requesting information, it is necessary toprovide a 6-figure grid reference for the site, the radiuswithin which searches are requested and to state thespecies, age of data and type of record required.

There are a number of information sources for bat roostrecords and sightings, including:

m Local offices of the Statutory Nature ConservationOrganisations (SNCOs). A valuable source ofinformation, especially as they receive bat roostreport forms from their network of voluntary batwardens. SNCOs should be contacted at the start of aproject to obtain any relevant data. However in manycases, offices do not hold these records in anaccessible format.

m Local Biological Record Centres (known as LRCs orBRCs). These are found in most counties and willundertake a data trawl of their records for a fee. A

list of active LRCs can be found on the NationalFederation for Biological Recording (NFBR) website(www.nfbr.org.uk).

m A Biodiversity or Nature Conservation Officer (alsoknown as county ecologists), who may have accessto records, is employed by some local, county ordistrict councils.

m Local bat groups usually hold a database of batrecords. The Secretary should be able to provide thename and contact details of the member whomaintains the database. The local bat group contactdetails can be obtained from the BCT website(www.bats.org.uk) or by calling the BCT NationalBat Helpline (0845 1300 228).

m Local wildlife trusts also keep bat records (seewww.wildlifetrusts.org). Sometimes the local batgroup is part of the local wildlife trust, so theinformation can be from the same source.

m County mammal recorders. These are volunteerrecorders who collate records sent to them aboutmammal sightings in their county. Contact details areavailable from the Mammal Society website(www.abdn.ac.uk/mammal/).

m Local or national mining history or caving groupsand clubs and caving councils may have usefulinformation. See the British Caving Association(http://british-caving.org.uk/) for details. A numberof cave systems have biological recorders andrecords are often published in club or regionaljournals.

m On-site personnel such as site security guards,caretakers or gardeners. They may provide anecdotalevidence that gives useful pointers but this may notbe robust or reliable enough to contribute to a deskstudy.

The study site may be on the boundary of two or moreorganisations, in which case they should all be contacted.

When using or referring to materials obtained fromexternal sources, rules of copyright should be noted andadhered to. There may also be restrictions on thecommercial use of internet resources.

3.6.2 Geographical extent of deskstudyIt is important to request information up to at least 1 kmfrom the survey site. Depending on the nature of theproposed project, its scale and the species likely to beaffected, a larger radius search area may be required (seealso Chapter 2). If there are, for example, Special Areasof Conservation (SACs) or other designated sites (e.g.Sites of Special Scientific Interest - SSSIs) within theradius selected for data searches, or if the extent andpotential impact of the proposed works is especially high,information should be requested up to 10 km away from




the site. In exceptional circumstances, such as where rarespecies that travel further than 10 km may be present,data trawls may need to be requested over larger areas.

Where the proposed work may affect a SAC, anAppropriate Assessment may be required (see alsoSection 2.2.3).

3.7 Site walkover surveyIt is unlikely that a desk study or data trawl (see Section3.6) alone would ever provide enough information tofully assess the value of an area for bats; therefore, aninitial visit to the site for a walkover survey is stronglyrecommended. Site walkovers are sometimes referred toas ‘scoping surveys’. They should aim to identify thepotential value of the habitat for bats. Information gainedfrom being on-site is a prerequisite to designing the typeand intensity of further survey, should it be required. Inthis way the walkover or scoping survey contributesimportant data to the ‘scoping exercise’ (see Section 3.8).It is an advantage to undertake the site walkover withknowledge of the desk study.

In larger projects, a walkover would normally be part ofan initial ecological appraisal. With the necessaryawareness, a professional ecologist can look for featuresof potential value to bats at the same time as recordingother features of ecological value. If bat or bird boxes arepresent, they should be checked for use by bats either atthis stage or during a subsequent survey (note thatsurveyor licences are required for bat box checking).Small sites may not necessarily require a specific sitewalkover for bats, as this assessment could be done inconjunction with a Phase I Habitat Survey16.

All site visits require a health and safety risk assessmentand appropriate permission for site access. The visitshould also be used to look for, and take note of,additional potential health and safety hazards (see Section3.5).

Surveyors undertaking the site visit are responsible foridentifying and recording areas and structures of potentialvalue for bats. The survey is usually undertaken bywalking over a site and observing the features present. Itshould be possible to identify those features most likely tobe of value for bats and these should be marked on a mapor plan. The walkover survey should record the value ofeach feature on site or in the landscape according to itspotential for use by bats for roosting, foraging orcommuting, taking into account its quality.

Guidance on assessing the value for bats of habitatfeatures within the landscape is given in Box 3.1. Acontinuum is presented between low and high potential.Individuals may wish to assign habitat as low, medium orhigh value for bats. For example, in a river valley thefollowing features would be identified as having highvalue to bats and therefore indicative of high likelihood ofbat presence:

m older trees/woodlands for foraging and roosting;m linear landscape elements e.g. hedgerows and

watercourses for commuting and foraging; andm built structures e.g. buildings and bridges for

summer roosting or hibernation.

Alternatively, features could be assigned a level of batpotential when they are examined in more detail (byclimbing/internal inspection/emergence – see relevantlater chapters).

16 Phase I Habitat Survey is a standardised system for surveying, classifying and mapping wildlife habitats including urban areas. For further information seeHandbook for Phase 1 Habitat Survey - A Technique for Environmental Audit (Joint Nature Conservation Committee, 2004) and the National VegetationClassification: Users’ Handbook (Joint Nature Conservation Committee, 2006).


21

The walkover survey should be undertaken in daylighthours, with sufficient time allowed to walk the wholearea.

Consideration should be given to whether the walkoverarea should be greater than the development footprint(impacts, for example, from lighting, could extendbeyond the site boundary) and extensive sites may requiremore than one visit for full coverage.

3.8 Selection of surveymethodsThe information gathered from the data trawl andwalkover should be collated and assessed in relation tothe proposed development and used to inform the typeand extent of future bat survey work. This is essentially a‘scoping exercise’ that identifies the possible effects ofthe development on bats and sets the future surveyobjectives. It should include consideration of appropriatesurvey methods and the level of survey effort and area

coverage that is proportionate.

As with the desk study and walkover survey, it isimportant to consider the area that the scoping exerciseshould cover. This could simply be the scheme footprintfor very small-scale proposals; however, for largerdevelopments, such as a new highway or a plannedresidential development, it should cover an area that takesinto account the wider landscape. When deciding theextent of any assessment, it is important to consider thespecies potentially affected and the nature of the proposedworks.

3.8.1. Appropriateness of surveymethodOnce it has been established that further survey isrequired beyond that conducted in the desk study andwalkover survey, the next step is to establish the mostappropriate survey in order to obtain adequate results forthe intended purpose.


Low

High

Confirmed presence

m No features that could be used by bats (for roosting, foraging or commuting).

m Small number of potential roosts, most likely less significant ones (i.e. probably notmaternity roosts or hibernacula).

m Isolated habitat that could be used by foraging bats e.g. a lone tree or patch of scrubbut not parkland.

m Isolated site not connected by prominent linear features (but if suitable foraginghabitat is adjacent it may be valuable if it is all that is available).

m Several potential roosts in the buildings, trees or other structures. m Habitat could be used by foraging bats e.g. trees, shrub, grassland or water.m Site is connected with the wider landscape by linear features that could be used by

commuting bats e.g. lines of trees and scrub or linked back gardens

m Buildings, trees or other structures (such as mines, caves, tunnels, ice houses andcellars) with features of particular significance for roosting bats.

m Habitat of high quality for foraging bats e.g. broadleaved woodland, tree-linedwatercourses and grazed parkland.

m Site is connected with the wider landscape by strong linear features that would beused by commuting bats e.g. river/stream valleys or hedgerows.

m Site is close to known roosts.

m Evidence indicates a building, tree or other structure is used by bats e.g.:• bats seen roosting or observed flying from a roost or freely in the habitat;• droppings, carcasses, feeding remains, etc. found; and/or• bats heard ‘chattering’ inside on a warm day or at dusk.

m Bats recorded/observed using an area for foraging or commuting.

Box 3.1 Guidance for assessing the value of habitat features within the landscape for bats and hence thelikelihood of bats being present.

NoteThere are no clearly defined categories of habitat value; rather there is a continuum from low to high value for bats. Expertjudgement will be required when assessing the relative value of a site for bats based on the features identified and the context inwhich the site or survey area is located.

Increasinghabitat

valuefor

bats

Survey method Building Tree Underground Swarming Foraging Commuting Migration(and Chapter in or bridge roost roost site area route routewhich it is described) roost

Internal inspection survey(Chapters 6, 7 & 8) 4 4 4

External inspection survey(Chapters 6 & 8) 4 4

Emergence/re-entry surveys(Chapters 4, 6, 7 & 8) 4 4 4 4

Backtracking(Chapter 4 & 8) 4 4

Manual bat activity surveys (Chapter 4) 4 4 4

Automated bat activity surveys (Chapter 5) 4 4 4 4 4 4

Catching surveys(Chapter 9) 4 4 4 4 4 4 4

Radio-tracking surveys(Chapter 10) 4 4 4 4



The purpose of the survey should be defined throughclear objectives (see Section 4.1.2) and these should guidethe selection of appropriate survey methods and theamount of survey effort required (see Section 3.8.2).

For instance, the objectives of the survey could be toestablish one or more of the following:m likelihood of particular buildings, structures, trees

and other features supporting bats;m presence or absence of bats e.g. in a particular

building, structure or tree;m number of bats present;m seasonal usage of an area or roost by bats;m specific features used within the survey area by

roosting bats;m areas and features of importance for particular

species whilst foraging and commuting;m bat behaviour that may be affected by a proposed

activity or development in terms of emergence,foraging, commuting or mating;

m opportunities for enhancement of bat habitat thatmay be possible within any given area;

m distribution of bat species in a landscape;m improved understanding of bat behaviour within a

specific species or at a particular location.

These objectives may require examination of one or moreof the following features or habitats:m Likely roost sites e.g.:

• buildings;• bridges and other structures;• trees; or• underground sites.

m Confirmed roost types e.g.:

• summer maternity roosts;• winter hibernacula;• mating roosts;• swarming sites; or• other/transitory roosts.

m Likely/confirmed foraging habitat (e.g. woodland,grassland, riparian, heathland, marsh/bog or other).

m Likely/confirmed commuting routes (e.g. hedgerows,treelines, watercourses or other) and/or migrationroutes at the local or landscape scale.

The objectives, location, type of bat habitat and type ofbat activity (e.g. roosting, foraging, commuting, mating,swarming or migrating) under consideration should thenbe used to select the most appropriate survey method(s)as described in detail in Chapters 4 to 10. Methods maytypically involve one or more of the following:m manual activity surveys - see Chapter 4;m automated activity surveys - see Chapter 5;m surveys of buildings and built structures - see

Chapter 6;m surveys of underground sites - see Chapter 7;m surveys for roosts in trees - see Chapter 8.

In more exceptional cases it may also be appropriate touse the more invasive survey techniques described below:m catching bats - see Chapter 9;m radio-tracking of bats - see Chapter 10.

A matrix depicting the survey methods that are availablefor various features used by bats is given in Table 3.2.Not all methods will be required in every case but acombination of methods is often used. For moreinformation see the individual chapters.

Table 3.2 Matrix showing the survey methods that are available for various features used by bats

Non-invasive methods

Invasive methods


23

3.8.2. Cautionary note – non-invasive versus invasive techniquesResolution 4.6 of the EUROBATS Agreement17 givesguidance on invasive survey techniques such as forcatching bats. It states that “the research being proposedshould not adversely affect the conservation status of thepopulation and should take account of the welfare ofindividual bats”. It also states that radio-tracking “shouldonly be used for well-organised and authorised projectswhere essential data cannot be acquired with lessintrusive methods”. Therefore when surveys areundertaken for development, non-invasive surveymethodologies should preferably be exhausted first beforeinvasive techniques are employed; where they are used,constant re-appraisal of the value of the information inrelation to the potential risks to the bats is essential.Disturbance caused by a survey should be the minimumrequired to obtain the necessary information and the leastintrusive methods possible should always be employed.

3.8.3. Cautionary note – provingabsenceIt is comparatively easy to determine use of a site by bats,but absence is more difficult to prove. It requires greatereffort to demonstrate beyond reasonable doubt that batsare not present or likely to be present.

3.8.4. Proportionality of surveyThe type of survey undertaken and the amount of effortexpended needs to be proportional to:

m the type and scale of the proposed activity or projectand its predicted impacts on bats;

m the likelihood of bats being present or affected;

m the species and numbers of individuals concerned;and

m the type of roost and/or habitat affected.

Greater effort should be expended in situations wherehigh numbers of bats are likely to be present and wherethere is a high degree of risk that they may be adverselyaffected. For example, the development of a large housingscheme is likely to have a range of effects and thereforemore detailed surveys at a landscape scale are likely to beappropriate. The amount of survey effort will also dependon the geographic region, the species found during thedata trawl and the type of roosting and foraging habitat inthe locality. If these factors suggest the likelihood of anAnnex II Habitats Directive species being present (one forwhich a SAC may be designated) then a greater level ofsurvey effort is likely to be required.

Figure 3.1 is a flow chart depicting the decision-makingprocess and gives guidance as to the level of survey thatis likely to be proportional according to the likelihood ofbats being present. It is worth noting that the type ofsurvey to be undertaken and amount of effort expendedcan often only be fully determined after visiting the site atleast once (see Section 3.7). Surveying for bats is often aniterative process, with later surveys being informed byearlier ones. It may often not be possible to determine allsurvey requirements at the start of a project.

A survey will only provide a snapshot of activity at thetime it is undertaken. Additional surveys may be neededwhere information on temporal or seasonal changes inactivity are needed, where a significant period of time haselapsed since the previous survey or where surveys havebeen limited by seasonal, weather, access or otherconstraints. An ecologist experienced in bat work shouldbe able to recommend when further surveys are required.If the survey and management or mitigation proposalshave been fully able to take into account potential use ofa site during other seasons, there is little merit in delayingworks, provided there is little chance of further surveysfinding any new significant facts.


17 EUROBATS Agreement Resolution 4.6 Guidelines for the Issue of Permits for the Capture and Study of Captured Wild Bats is contained within the writtenrecord of the Fourth Meeting of the Parties to the Agreement. Resolution 4.6 was subsequently amended by Resolution 5.5 at the Fifth Meeting of the Partiesto the Agreement. Both meeting records are available online from www.eurobats.org The UK is a Party to the Agreement.



Figure 3.1 Flow chart depicting the process of deciding what level of survey is necessary

(a) Undertake scoping study, designand undertake detailed survey toinform impact assessment – see

Section 3.8

Are there features with potential for bat presence?See Section 2.3.1

Will there be impacts on bats?

Yes No

Yes

UnlikelyLikely

Yes No

Go to (a)

Go to(b)

Design and undertake appropriate andproportionate survey to ascertain bat

presence/have confidence in a negativeresult – see Section 3.8

Are bats present?

Undertake data trawl andwalkover survey – see Sections

3.6 and 3.7

What is the likelihood of batsbeing present? – see Section 3.7

No surveyrequired

(b) Works shouldproceed withcaution andvigilance for

unexpected batpresence

Don’tknow

No

Yes No

Design worksto avoid orminimiseimpacts

Works shouldproceed withcaution andvigilance forunexpected

impacts

Are bats known to be present?


25

3.9 Survey timings


Figure 3.2 Overview of a year in the life of a bat

WINTER

SUMMER

January

February

March

April

May

June

July

August

September

October

November

DecemberHibernating

Hibernating

Starting to be active

Feeding on warmer nights

Young born

Mothers suckling young

Young flying and feeding

Young leaving maternity roosts Mating

MatingLaying down fat for winter

Females looking for maternity roosts

Pregnant females in maternityroosts

Hibernating

The timing of surveys depends in part on the ecology andbehaviour of bats, which changes markedly throughoutthe year and influences where and when they may befound in different habitats. See Figure 3.2 for a briefoverview of a bats’ annual cycle.

A large part of the bat year, October to May, can be spentin hibernation although on warm nights bats awaken to goout and forage.

As spring approaches, bats increasingly go out to feedand the period from May to early June is a time of intensefeeding activity to recover weight lost during the winter.During this time, females gather together at maternityroosts, sometimes moving from one roost to another tofind one with the right conditions. Some males may bepresent, but most roost elsewhere, either singly or insmall groups.

Most births occur in the middle two weeks of June but,depending on the weather, this can be as early as late Mayor as late as August. Once the babies are weaned, at threeto five weeks, the females leave the maternity roost anddisperse, both to gain weight before winter and to findmates.

During autumn, many Myotis bats travel to undergroundsites for an activity known as swarming which may beconcerned with mating and/or finding a hibernaculum.Males of other bat species establish mating territorieswhere they may fly or call specifically to attract a mate.

As the weather turns colder, bat activity reduces andforaging becomes restricted to warmer nights. Bats spendprogressively more time in torpor, before returning tohibernation.

Legend Optimal period

Sub-optimal period

Table 3.3 Recommended survey periods (adapted from Limpens, 2005) Site walkovers and scoping surveys can be carried out throughout the year.

Survey type

Manual bat detector surveys for commuting and foraging (see Chapter 4)

Manual bat detector surveys fordusk/dawn emergence/re-entry1

(see Chapters 4 and 6)

Automated logger/bat detectorsurveys (see Chapter 5)

Inspection of buildings and builtstructures for roosts2

(see Chapter 6)

Inspection of bird and bat boxes(see Chapter 6)

Mating roost/autumn swarmingsurveys (see Chapters 6 and 7)

Winter hibernation surveysincluding underground sites (see Chapter 7)

Tree surveys for bat roostingfeatures (by observation from theground) (see Chapter 8)

Tree surveys for active bats (batemergence or re-entry surveys)(see Chapters 4 and 8)

Catching surveys for active(commuting/foraging) bats3

(see Chapter 9)

Radio-tracking surveys3

(see Chapter 10)

J F M A M J J A S O N D

Notes1 The months shown are optimal for maternity roosts but there are other types of summer roosts for which othermonths outside these may also be optimal.

2 Although inspections of buildings can be made year round, summer roosts are more easily found during the monthsof May to August.

3 As best practice guidance the period for catching and radio-tracking bats should avoid periods of latepregnancy/early lactation or early flying juveniles, except in exceptional circumstances when the survey specificallyrequires it.



Table 3.3 provides recommended optimal and sub-optimaltimings for all types of survey methodology discussed in these guidelines. Although the survey timings areapplicable for most of the UK, they will vary according tothe geographic location of the survey, with bat activity in

Scotland commencing later than in most of England.They may also vary from year to year depending on thetiming of the onset of spring. As outdoor surveys areweather dependent, all surveys should be undertaken insuitable weather conditions.


27

3.10 Recording andreporting surveysIt is essential during planning and preparation of surveysto give due consideration to the recording and reportingof survey data. The results must be recorded in athorough and clear manner and it is recommended that astandard format is used. A general reporting template isgiven in Box 3.2. Not all parts will be relevant in everycase so it should be modified and used accordingly.

All survey records should include the following:

m date of the survey;m location of the survey (including six-figure grid

references);m list of the personnel who undertook the survey, their

qualifications and experience, including details ofrelevant licences; and

m species identified (supported where possible withobjective evidence e.g. sonograms).

In addition, reports of field surveys should include:

m weather conditions measured at intervals through thesurvey (temperature, humidity, wind speed anddirection, cloud cover, precipitation and light levels);and

m annotated diagrams and/or tables of bat activity andtransect routes showing species encountered, time,location and activity (e.g. direction of flight, feeding,commuting or other activities).

Further examples of the records appropriate to differenttypes of survey are given in later chapters. A reportingtemplate for roost visits can also be found in Appendix 3of the Bat Workers’ Manual (Mitchell-Jones and McLeish,2004).

Survey reports must make clear the limitations andconstraints of survey methodologies employed andexplain the impact of these on the conclusions that can bedrawn from the survey data. Frequency of visits andsurvey staff might change for a variety of reasons andwhen this occurs it is important to report it and interpretthe findings accordingly. It is also important to report andjustify a reduced (or increased) survey effort, if that wasthe case.

It is good practice for bat survey records resulting to besubmitted to Local Records Centres, local bat groupsand/or the National Biodiversity Network(www.searchnbn.net).

Once the first draft of a report has been written,comments should be sought (see Section 3.11).


1 INTRODUCTION1.1 Site description

Six-figure grid reference, description of location, brief habitat descriptions (including presence ofbuildings or other features of potential value to bats), size of site and photo/plan of site.

1.2 Proposed worksIf a development, what is proposed in terms of demolition, habitat destruction, renovation, timings, etc. If details of proposed works are not known, then state this here.

1.3 Aims of studyObjective of the survey undertaken and the aims of the report.

2 METHODOLOGY2.1 Desk study

List the organisations and sources from which bat records and information on sites of nature conservation importance have been requested and obtained. If no data sought or secured, then state this.

2.2 Field surveyNames of surveyors, their NE/CCW/SNH/DoENI bat licence numbers or other evidence of competency if surveyor is not licensed. The date of survey, time of start and end, weather conditions (temperature, humidity, wind speedand direction, cloud cover, precipitation and light levels).Survey methodology used, with reference to standard published methodologies, and way inwhich this seeks to achieve the survey objectives. Make clear which parts of a site were surveyed (e.g. survey of buildings only) and record the equipment used by each surveyor.

Box 3.2 Reporting template This is a general reporting template; not all parts will be relevant in every case so it should be modified andused accordingly.



3 RESULTS3.1 Desk study

Results of data trawl if sought and obtained. 3.1.1 Designated sites

Location of sites designated for their bat interest.3.1.2 Protected species

Location and age of bat records.3.2 Field survey

This information may be presented in many forms; as appendices, tables or text.3.2.1 Habitat description

Description of habitats of value to commuting, foraging and roosting bats.3.2.2 Bat roost survey

Full detailed descriptions of features that have potential value to bats, including location ofpotential access and roosting points as well as actual access and roosting places anddescriptions of bat signs and live bats found. This section may not be relevant if activity surveysonly were undertaken.Location of roosting features, height above the ground, direction in which they face anddescription of features with potential to support bats as well as actual bat roosts.Building/built structures - type of building/built structure, dimensions, age, construction, currentusage.Underground site – type of site (e.g. cave/mine and dimensions).Trees – species, dimensions, age, details of roost access.

3.2.3 Bat activity surveyResults of transect surveys, including analysis of bat detector recordings as well as sightingsduring survey. Results of emergence/re-entry surveys (if appropriate).Results of automated bat detector/logger surveys (if appropriate).Results should all be both quantitative and qualitative.

4 ASSESSMENT4.1 Constraints on study information

Weather, access, health and safety or any other constraints which have resulted in an inability toundertake a full survey and or make a full assessment of impacts.

4.2 Potential impactsImpacts considered both during construction and in scheme operation.

4.2.1 Designated sites.4.2.2 Bat roosts.4.2.3 Bat foraging and commuting habitat.4.3 Legislation and policy guidance

Details of UK and European legislation relating to bats, relevant national and local planningpolicy, national and local bat species biodiversity action plans.The purpose of this section is to put the findings of the survey and the impact assessment into alegal and policy context.

5 RECOMMENDATIONS AND MITIGATION5.1 Further survey5.2 Mitigation measures (not applicable to scientific/conservation surveys)5.2.1 Mitigation for roost sites.5.2.2 Mitigation for foraging and commuting habitat.5.3 Requirement for Habitats Regulations (EPS) licences

If bats or their places of shelter or protection are likely to be affected by the proposeddevelopment then consideration may need to be given as to whether a Habitats Regulationslicence should be sought.

6 SUMMARYA brief precis of the report’s findings.

7 REFERENCESAPPENDIX 1. Desk study dataAPPENDIX 2. Bat roost report formsAPPENDIX 3. Photographs


29

3.11 Consultees Consultations may be required at various stages of aresearch, conservation or development project. Thesestages may be:

1. during development of survey methodology;

2. following survey findings;

3. prior to, or following, submission of a planningapplication; and/or

4. when planning conditions are to be fulfilled.

Consultees may include any of the following:

m Countryside Council for Wales;m Environment Agency;m Environment Agency Wales;

m Environment and Heritage Service Northern Ireland;m local and national non-statutory nature conservation

bodies such as local bat groups and wildlife trustsand other relevant associations, for example, theBritish Caving Association in cases involvingunderground sites;

m Local Planning Authorities;m Natural England;m Scottish Environment Protection Agency; andm Scottish Natural Heritage.

The form of consultation will vary with the purpose andtype of survey. In all cases, SNCOs must be informedabout any proposals. Where certain species or protectedhabitats are involved, a more detailed discussion with theSNCO may be useful or required. In most cases it will befor the surveyor to provide the detail of, and justificationfor, the survey, but valuable suggestions forimprovements may also be obtained.




4.1 Introduction In this chapter, manual bat activity surveys are defined assurveys undertaken by people, the surveyors, observingbats outdoors in the field. The surveys do not disturb batsand are therefore non-invasive.

The surveyors usually work as a team, focusing onobserving and recording bat activity in a given area.Surveyors should always carry a bat detector, whichgreatly increases the ability to discover bat presence andcan assist in identifying the species. Night visionequipment can also help, allowing observations of batactivity in the dark.

Surveys using equipment such as automated loggers ordetectors left in the field are discussed in Chapter 5. Inpractice, non-invasive surveys of bat activity may use acombination of more than one method (manual andautomated) to maximise efficiency.

For information on assessing the need for a bat surveyand its planning and preparation refer to Chapters 2 and3.

4.1.1 Understanding bats’ use of thelandscapeWhen planning and undertaking manual bat activitysurveys it helps to know when and how bats use thelandscape, and this requires an understanding of batecology (see Figure 3.2 in Chapter 3 for a brief overviewof a bat’s annual cycle). Bats are highly mobile animalstravelling between:

m hibernacula and summer roosts; m one summer roost and another; m roosts and feeding areas; andm roosts and mating sites.

Surveys should always be set in the regional and seasonalcontext; for example, maternity roosts are not found inthe UK in October. Understanding bat behaviour is alsovital to interpreting correctly the findings of the survey ata later date.

British bats show a preference for habitats associated withbroadleaved woodland and water. In addition, they selectlinear features in the landscape (hedgerows, tree lines,river and streams), not only for commuting but also forforaging. This is particularly true of the Myotis speciesand pipistrelles. Bat activity is dictated by the locationand emergence of insects; bats know when and where istheir best foraging. This explains why seemingly good bathabitat sometimes has no bats, because they are feedingelsewhere.

Taking account of bat ecology, Table 4.1 givesinformation, where possible, for individual species in theUK in terms of foraging and commuting habitat,emergence time, range and distribution.

Table 4.1 provides a broad description of bat behaviourbut should only be used as a guide. Professionalsurveyors should always keep abreast of currentknowledge and research. Moreover, as with mostecological survey work, there is no substitute for practicalexperience. With greater experience comes an improvedsense of where bats are most likely to be within alandscape. However, experience can also lead to over-confidence, which can result in some potential habitatbeing dismissed without a survey.

This chapter aims to provide guidance on the approachand survey effort required to assess bat activity. Theguidance should be adaptable to most site surveysituations where an assessment of bat activity in the fieldis required.

Chapter 4

Manual bat activity surveys


31

18 Key references: Altringham (2003), Boye and Dietz (2005), Hutterer et al. (2005), Russ (1999) and Schofield and Mitchell-Jones (2003).


Table 4.1 Foraging and commuting habitat, emergence time, flying range, and distribution of resident breedingbat species in the UK18

Species

Common pipistrelle (Pipistrellus pipistrellus)

Soprano pipistrelle (Pipistrellus pygmaeus)

Nathusius’ pipistrelle(Pipistrellus nathusii)

Brown long-eared bat(Plecotus auritus)

Grey long-eared bat(Plecotus austriacus)

Foraging and commuting habitats, emergence time, range and distribution

Foraging and commuting habitat: Exploit a wide range of foraging habitatsincluding those associated with watercourses, woodland, grassland and built-upareas; may also feed around lighting.

Emergence1: From approximately 30 minutes after sunset.

Flying range: Feeding areas up to 3 to 4 km from their roost.

Distribution: Common throughout the UK and is the most commonly found bat inEngland and Wales.

Foraging and commuting habitat: Forage mostly over habitat associated withwater and follow water features when they travel.


Flying range: Feeding areas up to 3 to 4 km from their roost.

Distribution: Common throughout the UK. It is the second most commonly foundspecies but is more abundant in the north and west.

Foraging and commuting habitat: Forages over water and also along woodlandedges and rides.


Flying range: Nightly flying range to feeding areas is poorly known. European datademonstrate this bat is a long distance migrant (> 1,900 km recorded) and maycross from continental Europe to the United Kingdom seasonally.

Distribution: Information is currently too limited to give a distribution.

Foraging and commuting habitat: Live and forage around woodland and parklandwith old trees.

Emergence1: When dark, from approximately 60 minutes after sunset.

Flying range: Generally feed within 1-2 km of the roost; some bats will travelfurther.

Distribution: Common throughout UK wherever there is suitable woodland.

Foraging and commuting habitat: Forage in more open areas (when compared tothe brown long-eared), over grassland and along woodland edges.

Emergence1: When dark from approximately 60 minutes after sunset.

Flying range: Feed up to 6 km from the roost.

Distribution: A rare bat found in a few areas of southern England and in the Isle ofWight.



Natterer’s bat(Myotis nattereri)

Whiskered/Brandt’s bats(Myotis mystacinus/Myotisbrandtii)

Daubenton’s bat(Myotis daubentonii)

Bechstein’s bat (Myotis bechsteinii)

Noctule(Nyctalus noctula)

Foraging and commuting habitat: Hunts in tree canopies or close to foliage and byedges of water although at a higher level than Daubenton’s bat.

Emergence1: From approximately 40 to 70 minutes after sunset.

Flying range: Generally feed up to 3 km from the roost. Recorded to travel around60 km between summer and autumn/winter sites.

Distribution: Found throughout UK with the exception of the far north of Scotland;wherever there is suitable woodland.

Foraging and commuting habitat: Whiskered bats forage in a wide range ofhabitats including parkland, woodlands, flowing water and suburban gardens.Brandt’s bat forages more in woodlands and close to water bodies.


Flying range: Flying range is poorly understood. The distance between summer andwinter roosts is usually less than 50 km.

Distribution: Little is known about their individual distributions. Both species foundthroughout England, Wales and southern Scotland and parts of Northern Ireland.

Foraging and commuting habitat: Hunts close to the surface of slow-moving orcalm water. Will also forage in trees or along woodland rides, especially if these areassociated with water.

Emergence1: From approximately 40-60 minutes after sunset.

Flying range: Mostly feeds up to 6-10 km from the roost. Have been recorded totravel much further (100 km) between summer and winter roosts.

Distribution: Found throughout the UK, with the exception of some offshoreislands.

Foraging and commuting habitat: Forages in areas of closed-canopy woodlandclose to water. It will also forage along overgrown hedgerows and tree lines.

Emergence1: Early evening around sunset to 60 minutes after sunset.

Flying range: Typically feeds within 1 km of the roost. Probably travels furtherbetween summer and winter roosts.

Distribution: Southern England from Sussex to Gloucestershire; has been recordedin Shropshire and occasionally in Wales. Not recorded in Scotland or Ireland.

Foraging and commuting habitat: Flies high and straight to feeding sites overparkland, pasture, water and deciduous woodland. May feed around lighting.

Emergence1: Early evening in daylight; approximately sunset.

Flying range: European data demonstrate this bat is migratory (> 1,000 kmrecorded).

Distribution: Found throughout England and Wales and into southern Scotland.Not recorded in Ireland.



Leisler’s bat(Nyctalus leisleri)

Serotine(Eptesicus serotinus)

Barbastelle(Barbastella barbastellus)

Greater horseshoe bat(Rhinolophus ferrumequinum)

Lesser horseshoe bat(Rhinolophus hipposideros)

Foraging and commuting habitat: Flies high and straight. It forages mostly inareas of open habitat often over water or pasture.

Emergence1: Early evening from approximately 15 minutes after sunset.

Flying range: Feeds up to 14 km from its roost. European data demonstrate this batis a long-distance migrant with regular seasonal movements (>1,000 km recorded).

Distribution: Common and widespread in Ireland, rare and widespread in Englandand southern Scotland with a few records in Wales.

Foraging and commuting habitat: Forages mainly over pasture, parkland and alongwoodland edge. May also feed in suburban gardens and around street lamps.

Emergence1: Early evening from approximately 15 minutes after sunset.

Flying range: Typically forages within 2–6 km of roosts.

Distribution: Widespread but scarce in southern Britain; restricted to the south andsouth-west of England with occasional records in Wales. Not recorded in Scotlandor Ireland.

Foraging and commuting habitat: Forages along woodland edge and rides. Useshedgerows, streams and rivers for commuting.

Emergence1: From 20-60 minutes after sunset.

Flying range: Typically forages 5-6 km from their roosts; has been recorded travelup to 18 km.

Distribution: Widespread. Recorded from a line south of North Wales to the Wash.Not recorded in Scotland or Ireland.

Foraging and commuting habitat: In spring, greater horseshoes feed over cattle-grazed pasture and in ancient or semi-natural woodland. During summer, theyforage over hay meadows and silage fields.


Flying range: Typically feeds within 4 km of roosts but when habitat is restrictedtravel in excess of 12 km. Occasionally moves more than 100 km.

Distribution: Found in south-west England and south and west Wales, with anincreasing number of occasional records in mid- and North Wales. Not recorded inScotland or Ireland.

Foraging and commuting habitat: Flies to feed over areas of deciduous woodland,especially closed canopy. Will feed during the winter.


Flying range: Typically feeds within 2 km of their roost. Will travel 20 km betweenwinter and summer roosts.

Distribution: South-west England, Wales and western Ireland. Not recorded inScotland.

Note1 Time of emergence can vary through the year; it is also affected by the weather and the cover of local habitat.



4.1.2 Aims of surveyThe aims of manual field surveys are to:

m determine presence/absence of species i.e. thespecies present in a given area;

m determine the intensity of bat activity both spatiallyand temporally (to help estimate bat populations);

m determine the type of activity, most usually: • foraging (by feeding buzzes); • commuting (by high directional pass rates);• mating (by mating social calls);

m find roosts by tracking back bat flight paths orobserving dawn flight activity at roosts; and/or

m find emergence of bats from a building or builtstructure.

It should be noted that absence is near impossible toprove, as there is always a chance of finding a bat. Theirhigh mobility means that it is virtually impossible to rule out bats using any type of structure for roosting or habitat for foraging or as a flight path. When there is noconclusive evidence of bats, a potential for bat presenceshould be given.

These surveys are undertaken outdoors and the surveyormust have considerable field skills to be competent infinding and identifying bats and interpreting their activity.A licence is not required to undertake these surveys and it is worth noting that the training required for a roostvisitor or survey licence does not usually provide detailedtuition on the use of bat detectors and speciesidentification necessary for manual field surveys. Forskills required and details of training available seeSections 3.2 and 3.3 respectively.

The information that can be obtained from non-invasivedetector surveys (manual or automated) should preferablybe exhausted before any invasive techniques, such as mistnetting or radio-tracking, are used (see Section 3.8.1).

Activity surveys may be required for a range of habitatsand for varied development proposals, both of which mayinfluence the way in which a survey is conducted and thesurvey methods used. It is important to note that allmanual bat activity surveys are just a snapshot of batactivity in a small space at a particular time. To helpovercome these spatial and temporal constraints and tomaximise the survey effort, the following approaches areused:

m surveys are conducted when the bats are most likelyto be active (during warmer months and at dusk anddawn); and

m surveys concentrate on habitats and features that arelikely to be used by bats.

This is applied in practice by:

m undertaking surveys at dusk and at dawn; m spreading the individual surveys throughout the

summer months; andm performing transects over the area of interest or

being stationary at specific sites while observing andrecording bat activity, or a combination ofcontinuous/line transects and point counts. Surveying

by car or boat can also increase the area coveredcompared with surveying on foot (see Sections 4.6.2and 4.6.3).

To date, there is no statistically robust survey method fordetermining the bat species, population and level ofactivity in a given area. Moreover, consideration must begiven to determining bat activity on a large scale and overan extended period when the potential effects of thedevelopment are not fully understood or have notpreviously been assessed, for example, with wind farmproposals.

4.1.3 Identifying bats byecholocation and flight Identification of bats in the field is aided by carefulrecording (e.g. a sound recording with commentary) of asmany factors as possible including:

m echolocation calls;m pattern of flight;m apparent size;m location and habitat; m type of activity – feeding, commuting, social calling;m time of activity; andm weather conditions.

The value of field experience cannot be over-emphasised.Even with moderate experience it is possible to use batdetectors to separate bats into four groups based on thetype of echolocation call they use (particularly thefrequency ranges and relative amplitudes involved)although the information gained will be of limited value.The four groups are:

m horseshoe bats;m lower-frequency bats (also sometimes referred to as

the bigger bats): noctule, serotine and Leisler’s bat;m pipistrelle bats; andm everything else (which includes barbastelle, long-

eareds and Myotis bats).

With further experience these groupings can be splitfurther using heterodyne or tuneable detectors to listen tothe spacing between calls, the relative loudness and thechange in pitch or note of the call as you tune through itsfrequency range. These call parameters can also bemeasured if you record the calls with a broadband batdetector (frequency division or time expansion) andanalyse them using appropriate software. As well assound, the manner, height and location of flight alongwith the habitat and time of observation will assist withidentification. Be aware that results from detectorencounters are biased towards bats that use louder andlower frequency calls. Quiet bats like Bechstein’s may bepresent and not picked up by a detector unless they are afew feet away. Appendix 1 contains more detail on howto identify bats using ultrasound calls (including soundanalysis) and flight patterns.

When using a bat detector to survey, well-chargedbatteries are essential as low batteries severely affect thesensitivity of a bat detector. The geographical location


35

should be considered and notes about the surroundingsand flight pattern should be taken, if post-survey soundanalysis is to be carried out. Ideally, the analysis shouldbe done as soon as possible after the survey. Soundanalysis is a useful tool and may help to identify speciesotherwise missed, but it has its limitations, especially for bats in cluttered habitats and where species haveoverlapping call parameters such as Myotis species.

It should be noted that social calls are more common inautumn than at other times of year. Pipistrelle social callssound a lot like noctule calls to the inexperiencedsurveyor using a heterodyne detector. Pipistrelle socialcalls also tend to travel further because they are lowfrequency, so they may be heard without an associatedtypical echolocation call. Mothers may make distinctivesounds towards their young, and juveniles may alsoproduce atypical calls when learning to echolocate. Foridentifying social calls, the use of time expansiondetectors to make recordings for sound analysis isadvised.

When surveying for bats always be prepared for theunexpected; bats do not read the guidance and there isstill a lot to learn.

4.2 EquipmentAppropriate equipment is essential for surveying bats; thebat detector is the most useful tool and no manual fieldsurvey for bat activity should be attempted without one.Bat detectors use three methods to convert bat ultrasoundto a range audible to humans; the advantages anddisadvantages of each type of detector are given in Table4.2, along with those of night vision scopes and low-lightvideo cameras.

It is good practice to make a sound recording of the

survey using a broadband detector for future analysis.Analysis of the broadband recording on a computerenables objective evidence to be produced to support fieldobservations.

Equipment to measure key weather parameters, especiallyat the microclimate level, is also needed. Essential andrecommended equipment is listed in Table 4.3 and Table4.4 respectively.

Equipment often fails, so spares should naturally formpart of the survey kit. For manual field surveys alwayscarry a spare bat detector, torch and batteries.

Manual bat activity surveys are limited by the equipmentused. Detection methods bias the results of observationsin many ways:

m Bats vary in the loudness of their call so louder batsare more likely to be detected by a bat detector.

m The area and range of detection equipment such asnight vision and bat detectors is limited, so bats highin the canopy are less frequently recorded.

m Microphones in bat detectors vary in sensitivity so ifa bat detector is changed for a more sensitive model,this can cause an apparent increase in the number ofbats recorded.

Potential bias caused by manual bat detection methodsshould be taken into account when interpreting theresults. If the bias cannot be adjusted (or qualified)through expert judgement and there is a need to confirmthe presence of individual species, rather than infer theirpresence by the habitat or nearby records, or themitigation cannot be undertaken without confirming theirpresence, then the manual bat activity survey techniquesshould be supplemented by other survey methods (such ascapture and possibly also radio-tracking - see Chapters 9and 10) subject to the constraints detailed in Section 3.8.


Detector type

Heterodyne detector

Frequency divisiondetector(broadband)

Advantages

• Most familiar type of batdetectors and pleasant to listento.

• With expertise can identify mostspecies in the field at least tospecies group.

• Broadband recording (all speciesheard at once) with somefrequency division detectors (e.g.Petersson D230 and Batbox Duet).

• Records continually through thesurvey so nothing is missed.

• With sound analysis, can be usedfor identifying some bats tospecies level and others to speciesgroup.

• Many more calls recorded in agiven time period than with time

Disadvantages

• No sound analysis possible.• Narrow band listening (species

outside listening range can bemissed).

• Louder bats bias the estimate ofpopulation as they are the onesmost often heard.

• Hear all the ultrasound clutter.• Sound analysis not as good as

that produced from timeexpansion using spectrographicmethods as the sonogramscontain less information.


• Low frequency, frequency-dividedcalls contain little information forthe sonogram.

When best used

• Non-professional surveysor in professional surveyswhen in combination withbroadband detector types.

• Professional consultancysurveys in conjunctionwith recording equipmentwhen identification togeneric level is adequate,especially when quantityrather than quality isimportant.

• In combination withheterodyne or timeexpansion detector.

Table 4.2 Advantages and disadvantages of different detection methods for manual bat activity surveysincluding bat detectors, night vision scopes and video cameras.



Time Expansiondetector(broadband)

Night vision scope

Video camera (with lowlight recordingcapability)

expansion and hence lesslikelihood of identification basedon anomalous calls. Preservationof repetition rates and rhythmsto aid recognition in the field bysome detectors (e.g. PeterssonD230 and Batbox Duet).

• Broadband recording (all speciesheard at once).

• Preserves the detail of the highfrequency sound.

• With sound analysis can be usedfor identifying some bats tospecies level.

• Can replay the sound inheterodyne mode (e.g. PeterssonD240x) or through some soundanalysis software.

• Can observe bats that cannoteasily be heard.

• Can observe bat flight behaviourand its location.

• Provides a visual record.• Can observe bats that cannot

easily be heard.• Can observe bat flight behaviour

and its location.

• Only one harmonic is sampled.• Cannot replay the sound in

heterodyne mode (although somesound analysis software will re-create the sound).

• Does not continually record, sosome bats may be missed.However, if the recording time iskept short (<100 ms), thedetector will catch a selection ofcalls from most passes thoughthere will be a trade off in termsof identification potential.

• False triggers by non-batultrasound in automaticrecording modes.

• Resolution not sufficient fordifferentiating whiskered,Brandt’s and Bechstein’s and canbe limited in certain situationsfor other species.


• Can have a narrow field of viewmaking it difficult to follow batsin flight.

• Cannot pan quickly.

• Cannot pan quickly.

• Professional researchwork when identificationto species is necessaryand the details of thecall are essential,especially where qualityrather than quantity isrequired.

• Professional consultancysurveys in combinationwith other detectorswhen selected calls maybe recorded for analysis.

• Used to observe batflight behaviour (e.g. onexit surveys when theexit is dark).

• Best used in conjunctionwith an infrared lightsource.

• Used to observe batflight behaviour (e.g. onexit surveys when theexit is dark).

• Can act as additionalobserver.

• Best used in conjunctionwith an infrared lightsource.

Use

Assists in finding bats.

Sound record of survey for subsequent computer analysis.

Greatly increases the sound quality on the detector - also allows two methods of listening tobats (e.g. heterodyne and frequency division).

Spectrographic sound analysis.

Instruments to record temperature and humidity (wind speed and direction and cloud covercan be estimated by eye).

To record findings.

To light the way, for safety and to aid recording notes.

For orientation.

Equipment

Bat detector

Recording equipment (varioustypes - analogue and digital)

Headphones

Computer with spectrographicsound software

Hand-held temperature andhumidity meter

Plans

Torch/head torch

Compass

Table 4.3 Essential equipment for manual bat activity surveys


37

4.3 TimingManual bat activity surveys should be programmed totake place when bats are most likely to be active. Starttimes will vary throughout the year, according to the duskand dawn times.

In practice, surveys are normally undertaken as:m dusk survey only;

m dusk and dawn surveys with a rest break between thetwo;

m dusk to dawn surveys (as undertaken for radio-tracking studies but can provide valuable informationwhen conducted as manual activity surveys); or

m dawn survey only.

Table 4.5 gives guidance on the period of time the surveyshould be undertaken for a series of common surveyobjectives.


Use

Measuring the height of a roost.

Viewing bats in the dark (e.g. to observe foraging in the canopy).

Communication with other surveyors and to hear progress of survey. Channel can remainopen for continuous listening.

Accurate positioning and recording of time and location on driven transects.

Measure ambient light levels.

Used in conjunction with night vision allows for non-invasive viewing of bats.

For emergence counts.

Inspection of potential bat features.

Making notes of survey (some bat detectors have this feature).

Stopwatch and recording times.

Equipment

Clinometer

Night vision equipment

Two-way radio (walkie-talkie)

Global Positioning System (GPS)or Satellite Navigation System(Sat Nav)

Lux meter

Torch with infrared filter

Tally counter

Close-focusing binoculars

Voice recorder

Watch

Table 4.4 Other equipment useful for manual bat activity surveys

Dusk survey1

sunset to 2-3 hours after sunset2

1/4 hour before sunset to approximately 2 hours after sunset3

sunset to 4 hours after sunset

Notes

1 These surveys are not normally undertaken as one-offs and are usually part of a series see Table 4.7.

2 When the site area larger than 1 ha and within 4 km of a greater horseshoe bat roost, 3 hours is required.

3 Some bats may emerge earlier and 1/2 an hour before sunset may be more appropriate.

4 Some bats may return to their roost after sunrise.

Dawn survey (if undertaken)

2 -11/2 hours before sunrise to sunrise4

2 -11/2 hours before sunrise to sunrise4

-

Survey objective

Bat activity away from roost(all species)

Bat emergence from and re-entry to roost(all species)

Mating activity (all species)

Table 4.5 Recommended length of time over which manual bat surveys should be conducted

4.4 Survey area The area of coverage for the survey depends on thefollowing:

m size and complexity of the development;m proximity of designated sites (e.g. SAC or SSSI);m value of surrounding habitats for bats; andm known bat populations in the area.

As a starting point, it is recommended that whenassessing high or moderate value sites (see Box 3.1) thesurvey should extend to include all structures and areasthat are affected by the development and which areassessed (after the data trawl and walkover - see Sections3.6 and 3.7) as having the potential to be important forbats. The survey may need to extend beyond the siteboundary; for example, light spillage may disturb a flightcorridor outside the development. The survey may alsoneed to be extended when there is the potential to affectdesignated sites or other known bat populations. Forphased developments, the entire site should be surveyedat the start.

4.5 Survey effort andfrequency Having defined the survey area, deciding on the numberof surveyors per unit area is more difficult. Table 4.6gives guidance on the number of surveyors perdevelopment area (ha). However, the optimum number ofsurveyors will depend not only on the area ofdevelopment but also on the bat potential of the site interms of the species expected to be present, the number ofpotential roost sites and the availability of suitablehabitat. Ease of access and navigation around the site mayalso be a factor in determining the number of surveyors;for example, a site with many buildings will require moresurveyors to survey for emergence activity. The numberof surveyors will also be influenced by the type andnumber of bat detectors available plus the objective of thesurvey. More heterodyne detectors will be needed tocover an area thoroughly than if using broadbanddetectors. The bat potential, and hence the requirednumber of surveyors, is decided after the data trawl andpreliminary walkover survey.

When undertaking surveys for development, the level ofsurvey effort should be proportionate to the likely use ofthe site by bats and the potential effects of the proposeddevelopment on the species present. The effort is closelyrelated to the habitats present; for example, more effort isrequired when the site is predominately deciduouswoodland and a river corridor than if it were mostly apaved car park. However, the regional location of the sitealso needs to be taken into consideration, with increasingspecies diversity (and perhaps also density) to the southand west of the UK.

In practice, manual bat activity surveys are undertaken onsites that are generally a mixture of habitats and thesurvey effort is decided using the following factors:

m area and value of the habitat which is of potentialuse by bats (hedgerows, tree lines, river or streams,etc.);

m location (to the south and west of the UK there aremore bat species and perhaps a higher number ofbats per unit area); and

m linkage to potentially good bat habitats outside thedevelopment area; these may be many kilometresaway. A thin corridor may be important tocommuting bats.

Table 4.7 gives guidance for the minimum number ofmanual bat activity surveys that should be conducted inorder to ensure that sufficient survey visits are undertakento observe bat activity and to have confidence in anegative result. In this table, site habitat has beensimplified into moderate to high and low value. Thisshould have been indicated by the data trawl and thewalkover. These should also have indicated the potentialpresence of bat roosts.

Note that the proximity of a greater horseshoe bat roostcan override the site value of the habitat, and there isseparate published guidance for greater horseshoe batsurveys in the Bat Mitigation Guidelines (Mitchell-Jones,2004).

Site area (ha) The site has a moderate

likelihood of bats (see Box 3.1)

< 5

5 to 25

25 to 75

75 to 200

Number of surveyors

2

4

6

8

Notes on the number of surveyors

1 Two surveyors is the recommended minimum for health andsafety reasons; surveyors may have to work in pairs to satisfythe risk assessment.

2 If the required number of surveyors is not available, then thesurvey should extend over several nights to keep the area/surveyor ratio roughly constant.

3 Automated systems (e.g. data loggers) can be used in placeof some of the surveyors. This is especially recommended forlarge areas as this can be an easy way to extend the surveyperiod.

4 Driven transects use fewer surveyors per unit area; however,the value of these is not equal to that of a walked transect,which would be undertaken over the same length of time butin a smaller area.

Table 4.6 Recommended number of surveyors per sitearea using broadband detectors (Not applicable toemergence surveys)




39

4.6 MethodsVarious methods can be employed during manual batactivity surveys in order to gain an understanding of howbats use an area. A single survey method is rarely used inisolation; for example, walked and driven transects mayboth be carried out at the same time and complemented by automated survey techniques (see Chapter 5). It isrecommended that driven transects are used to supplementrather than replace walked transects, as few proposeddevelopments are able to be wholly surveyed from a road.Moreover, the road network must be such that it wouldprovide useful information about bats in the area.

Peak activity is seen at dusk and dawn and there can be alull in activity in the early hours of the morning, althoughat autumn swarming sites bats remain active for severalhours after dusk (see Chapter 7). For this reason surveysare usually concentrated in the hours after dusk. However,it is recommended that, as a minimum, one dawn surveyis undertaken as this invariably increases theunderstanding of how bats use the site and can beparticularly useful in locating roosts by detecting batsengaging in dawn swarming activity outside the entrancesto their roosting sites.

4.6.1 Walked transects PreparationThe chosen route should not be walked for the first timein the dark. The site should first be visited in daylight toplan the route and ‘listening station’ stops, and to walkthe whole route, noting how long one circuit takes. The

aim is to ensure that the whole transect takes no morethan three hours starting about half an hour before sunset.If the site to be surveyed is small, more than one circuitmay be achieved in one survey session. At a large site,transects may need to be undertaken over severalconsecutive nights to cover the whole area.

Using aerial photographs, an Ordnance Survey map and a daytime walkover, a route should be chosen that willincorporate habitat features with potential for use byforaging and commuting bats. These may include, if present on the site, woodland, woodland edge,hedgerows, lines of trees, stream corridors, lake or pondedges, scrub margins and grassland, especially semi- orunimproved pasture.

MethodTransects are walked usually with a broadband batdetector connected to a recording device, or the recordingdevice may be an integral part of the detector. Heterodynedetectors cannot be used for analysis of frequencyinformation. Some detectors, such as the automatedAnabat or the Tranquility, can be hand-held throughoutthe walked transect, leaving them to record automaticallyor when ultrasound triggers the recording. Recordings caninclude the exact time of the bat pass and these can bechecked against the surveyor notes during later analysis.Other detectors can be set to record either automaticallyat an ultrasound trigger, or used on a manual setting. Inmanual mode, the observer pushes a button to start thesample when ultrasound is heard, and then listens to thetime-expanded sequence on a loop stored in the detectormemory (Petersson detectors), either recording ordiscarding each sample in turn. Some detectors enable the


Site/habitat being surveyed

Moderate to high value

2/3 surveys1 during March2 – September3.Optimum period June - August.At least one of the three surveys shouldcomprise dusk and dawn (or dusk to dawn)within one 24-hour period.

2/3 surveys1 during May – September.Optimum period May – August.At least one of the three surveys shouldcomprise dusk and dawn (or dusk to dawn)within one 24-hour period.

Notes1 Best practice is to space the surveys evenly through the optimum period.

2 Surveys should not start before April in the north of the UK; some delay may also be caused by the weather.

3 Season can be extended to October to November if working in south-west England or surveys for mating activity are required,although particularly cold weather will render this inadvisable.

4 When the site area is larger than 1 ha and within 4 km of a greater horseshoe bat roost, the Bat Mitigation Guidelines (Mitchell-Jones, 2004) recommend two surveys in each month between May and September. Advice from the SNCOs should be sought andthe same may be applied to other species also (in particular, other Annex II Habitats Directive species).

Low value

2/3 surveys1 during March2 – September3.Optimum period June - August.

2/3 surveys1 during May - September.Optimum period May - August.

Location of activity survey

In habitat away from knownroosts (bat detector transects)(all species)4

At known roosts (duskemergence or dawn-re-entrysurveys)(all species)

Table 4.7 Minimum visit frequency and timing for manual bat activity surveys away from and at roosts (see alsoTable 3.3 for recommended survey periods and Box 3.1 for guidance on habitat values)

observer to listen in heterodyne mode as well as recordinto either time expansion or frequency division.

The transect should be walked along a predefined routeand at a steady speed. It can be useful to incorporatebetween 10 and 12 listening station stops interspersedalong the chosen route. The length of each stop may be 2to 5 minutes, depending on the overall length of thetransect, and bearing in mind that it should take no morethan 3 hours overall. Choosing easily identifiable,permanent features such as ‘veteran oak tree’, ‘outsidefarm barn’ as listening station stops ensures that thetransect is repeatable by others, if necessary.Alternatively, the transect can be walked without stops,particularly when using broadband detectors.

Transects undertaken for conservation and monitoring aregenerally different to those undertaken for developments.A common objective in conservation and monitoringsurveys, such as those undertaken for BCT’s National BatMonitoring Programme, is to observe changes over time(i.e. of population and species). To achieve this, thesurveys are at randomly allocated sites, standardised andmade repeatable. For monitoring purposes, it is important

that each transect starts at a defined time, follows a setroute and is undertaken at the same time of year.

When using transects to monitor bats for a development,the objective is to find not only an estimate of populationand the species present but also all parts of the site whichare used by bats. Therefore, it is an advantage to:

m undertake transects in reverse (or clockwise and anti-clockwise in the same survey);

m change the transect to look at a different area; and/orm stop and start transects depending on the level or

type of activity.

As for all activity surveys, walked transects are acombination of observation and listening. It is useful to

develop a survey sheet (see Table 4.8 for an example) onwhich the species seen/heard, the time and the location(on or between listening station stops) can be noted.Alternatively, the comment facility available on somedetectors can be used for this purpose.

4.6.2 Driven transects Driven transects can cover much larger areas than walkedones. They can be one long transect or a series of shortones (where travel between the series records no data)and can also incorporate listening station stops. Driventransects may consist of more than one circuit of the routein the case of a small site to be surveyed, or partialtransects undertaken over several nights, if the site is verylarge.

PreparationUsing aerial photographs, an Ordnance Survey map and adaytime visit, a route should be chosen that willincorporate habitat features with potential for use byforaging and commuting bats. It is recommended that anorange rotating beacon be mounted on the vehicle roof as

a warning to other road users and that a sign be placed on the vehicle saying “SURVEYING”. It is alsorecommended that the authorities (for example, policeand local councils) be informed of the survey.

MethodThe transect is driven along a predefined route and at asteady speed 15 mph (24 kph), continually recording batsounds with a detector mounted out of the window orsunroof on the hedgerow side of the vehicle at a 45°angle. A time expansion or frequency division detector isnormally used for the recording and this is subsequentlyanalysed using sonogram analysis software. The use oftime expansion bat detectors allows for the best chance ofidentifying bats to species level. The location of batcontacts can also be estimated from a simultaneous



Table 4.8 Example of walked transect survey sheet

Project Date Sunset Weathername

Surveyors Bat passes heard

Station Location Time Common Soprano Myotis or Large bats Othernumber pipistrelle pipistrelle long-eared (noctule,

serotine,Leisler’s)

1

2

3

4

5


41

GPS/Sat Nav record of the transect route. During thesurvey, the ambient air temperature, humidity, cloudcover, wind speed and direction are recorded. On a planof the transect route, the locations of street lighting(including bulb type e.g. sodium or metal halide) arerecorded. Lux levels may also be recorded. The transectshould preferably be driven with dipped headlights.

A speed of 15 mph will still allow for a recording to beinterpreted down to species level. At higher speeds (e.g.30 mph), interpretation of the recording is difficult andunreliable; however, such surveys can be used to simplydetect the presence of bats.

This transect methodology can cover a large area withrelatively few surveyors and does not require highlytrained individuals. Analysis of the recording requiresconsiderable expertise and time needs to be allocated forthis task.

Interpreting the results should take into account that thereis a reduced chance of recording the same bat twice whencompared to walked transects; however, it is still possiblethat a single bat can be recorded more than once during atransect survey.

Where it is safe to do so, this transect method can becarried out on a bicycle.

4.6.3 Boat transects Boat transects can also cover larger areas than walkedones and may permit access to a waterway that does nototherwise have easy access. It is recommended that therelevant authorities (for example, police and BritishWaterways) and land or river owners be informed of thesurvey.

PreparationIt must be ensured that the craft used is suitable for thewaterway to be surveyed, that there is sufficient depth ofwater, and also adequate headroom beneath bridges oroverhanging vegetation.

MethodThe transect is conducted along the waterway, close to thebank (distance will depend on the type of waterway). Thesame detectors can be used as in walked or driventransects. The detector should be held or fixed angleddownwards at 45° to the water at the side of the boat (i.e.towards the bankside). Alternatively, switch betweenhorizontal and downwards, in order to detect bats flyingnear to or within bankside vegetation as well as thoseflying close to the water’s surface.

As for the driven transect, GPS can be used to record thelocation of bat sightings, and ambient temperature,humidity, cloud cover, wind speed and direction shouldbe recorded. It is worth noting that close to the bankambient light levels may be greatly influenced by lightspill from buildings or from towpath lighting. Light levelscan be recorded using a lux meter.

4.6.4 Backtracking to find roosts PreparationThe approach to locating roosts using manual fieldsurveys was first developed in The Netherlands and iscommonly referred to as ‘backtracking’. The technique isbased on four principles:

1. The earlier the bat is seen at sunset or the later it isseen at sunrise, then the closer it is likely to be toits roost (the exact time depends on the speciesunder study; see Table 4.1).

2. Bats fly away from their roost at sunset andsurveyors should move towards flying bats tolocate the roost.

3. At sunrise bats fly towards their roost andsurveyors should move in the same direction as thebats to locate the roost.

4. At sunrise some bats species swarm at roostentrances for between about 10 and 90 minutesbefore entering.

MethodIn the evening, surveyors should search for bats from 30minutes before sunset, noting the time bats areencountered and the direction of flight: e.g. westcommuting (arrows on a detailed plan with time andspecies are invaluable). This information is pooled fromall the surveyors on to a map to identify potentialcommuting routes and possible roost sites.

Beginning 21/2 to 2 hours before dawn surveyors shouldsearch again, this time for returning bats, starting with thepotential flight routes identified the previous evening.Surveyors should be vigilant for a concentration of flightactivity as bats return to their roosts.

Although this technique is biased towards early emergingspecies with loud echolocation calls and those which formlarge roosts, it is possible to locate roosts of any speciesusing this method.

4.6.5 Dusk emergence and dawn re-entry surveysPreparationEmergence and re-entry surveys are the primary methodsfor locating roosts in trees, buildings or built structures, as bats are not always found by internal and externalinspection surveys (e.g. if the bats roost in areas thatcannot be searched and/or leave little or no visible trace).

An emergence survey can also give a reasonable estimateof the number of bats present. The tree, building or builtstructure should be inspected in daylight before thesurvey is undertaken, using binoculars where necessary,in order to assess the features, all potential exit locationsand the number of surveyors required.

All the surveyors should be briefed of these findings and informed of the areas on the tree, building or builtstructure they are to watch. Sufficient surveyors should be used so that all aspects of the tree, building or builtstructure can be viewed at one time; for a simple tree orregular four-sided building two surveyors are adequate




but it is better to have some surveillance overlap.Surveyors should count a set area to avoid doublecounting. In public places the surveyors should be able tosee each other; additional surveyors may be required andfluorescent jackets are a useful aid to visibility.

Some bat species do not emerge until 1 hour or more aftersunset and the use of night vision equipment and batdetectors should be considered to aid observation andpossible identification of species.

MethodSurveyors are positioned so that all possible bat exits canbe observed at one time and the line-of-sight should notexceed 50 m. The length of time to undertake emergencesurveys is given in Table 4.5 and the period in the yearduring which they can be carried out is given in Table3.3.

Observation of a tree/building for over two hours requiresvigilance and concentration. The bats are more easilyobserved against a light background, such as the eveningsky, and with a bat detector to assist in detecting bats.

Dawn surveys are particularly revealing as bats generallyspend more time returning to their roost than emergingfrom it, giving the surveyor more time to see the bat andentrance location; the dawn light can also be morefavourable. August is an especially good month toobserve maternity roost re-entry, as young flyers can beinexperienced and are often highly visible when returningto the roost. It should be noted that, as with emergencetimes, different species also vary in the time that theyreturn to the roost. For example, pipistrelles and noctulesmay return when light levels are relatively high comparedto other species. Periods when female bats are lactatingwill also affect the pattern of emergence and returning atmaternity colonies over the course of the night andmorning.

To obtain a reasonable estimate of the number of batspresent, all bat exits and re-entries are counted. There isusually more than one roost exit, so the number of batspresent in a tree, building or built structure cannot becalculated until all the surveyors report their numbers atthe end of the survey.

43

5.1 Introduction Automated systems can be employed to achieve a greaterlevel of survey intensity than with manual bat detectorsurveys, and for minimal extra survey effort. They canallow several sample points to be surveyed at the sametime, providing more comparable results, or be used toprovide a more flexible timetable for surveying. There aretwo types of systems that can be used to record batactivity remotely in the absence of a surveyor: remote batdetector recording systems and automated activitylogging systems.

Remote bat detector recording systems consist ofbroadband detectors (frequency division or timeexpansion) attached to a recording device. Depending onthe system used, this produces either a log of bat passesover time or records calls for later sound analysis,enabling an attempt to be made at species identification(see Table 4.2 for advantages and disadvantages of thedifferent detector types).

Automated activity logging systems use a devicetriggered by sound (via a detector) or movement (crossingan infrared beam) and record these as events onto a datalogger. Such systems have the potential to collect longruns of quantitative or semi-quantitative data on roost use,with minimal effort. The ideal automated activity loggingsystem would count the number of bats going into and outof the site or derive an index of activity, identifying eachbat to species and logging the time of each event. Inreality, counting individual bats and identifying thespecies can be very challenging.

Night vision camcorders or cameras activated bymovement can be used to record bat activity and possiblybat behaviour without the need for an observer to bepresent throughout the survey period. These systems aredeployed in the field at specified sample points, forexample, to observe a roost entrance.

Automated techniques of both bat detector recording andactivity logging can be undertaken as an alternative towalkover surveys in some circumstances but do notprovide observer notes, which are often essential toidentify certain species. They are best considered as acost-effective way of increasing sampling effort andideally, both techniques would be used in acomplementary manner.

For information on assessing the need for a bat survey andits planning and preparation refer to Chapters 2 and 3.

5.2 EquipmentTechnology is changing rapidly and new systems arebeing developed that allow equipment to be leftunattended in the field for long periods. Appendix 2describes some systems that have been used regularly inthe UK up to the time of publication but readers areadvised to consult the relevant specialist suppliers fordetails of any new systems that are available or indevelopment. Background information on the differenttypes of systems available is also given in Glover andAltringham (2007).

Fairly simple systems can be put together with littletechnical knowledge, using commercially availablecomponents, but there can be advantages incommissioning specially designed systems. This isespecially the case for large-scale surveys or where thereare not enough observers available to provide thenecessary cover within the given time or budget.

As they are left in the field unattended, automatedsystems have problems of security and power supply.They can often be costly to purchase and require a secure, vandal-proof site. It is not always possible toweatherproof the equipment completely nor to find a sitethat will remain dry. Equipment running on batteries mayrequire regular battery changes or the use of a solar panelor other means of natural energy generation in order tocharge the batteries.

A recent case, where a bat detector recording systemplaced on a bridge was the subject of a security alert and‘bomb’ disposal, emphasises the need to advise therelevant authorities (e.g. police, Highways Authority) toprevent the destruction of expensive equipment anddisruption to the public.

5.2.1 Bat detector recording systemsComplete systems that are designed to be left out in thefield to detect and record bat calls are commerciallyavailable. It is also possible to build a system bycombining standard bat detectors and recording devicesthat use tapes, mini-discs, memory cards or hard diskMP3 recorders. This option requires some electronicsexpertise but can provide a cheaper system or more units.This could be an advantage particularly for bat group orstudent projects, where funding is limited but skilledvoluntary help may be available, or where there is agreater risk of the units being lost or damaged.


Chapter 5

Automated bat activity surveys



Commercial systems are more expensive to buy but therecan be cost savings in the time taken to set up the systemand to download and analyse the data. For example, onesystem can store many nights’ recordings on one CompactFlash (CF) memory card and may include software thatcondenses the data, making it much quicker to scan forbat calls than using a separate recording device thatcontains bat calls interspersed with ‘white noise’.

Some of the considerations that will influence anydecision about the best system to use for a particularsurvey are:

m information required from the survey; m number of sample points and therefore how many

units are required;m type of detectors to be used (see Table 4.2 for

advantages and disadvantages of the different types);m other methods available (e.g. to complement activity

loggers);m number and availability of surveyors;m level of surveyor expertise (in the field, in electronic

systems and in sound analysis); andm security of site and protection from the elements.

Automated systems are relatively easy to set up anddeploy in the field. Once the system is place, data can be downloaded and the battery changed by unskilledpersonnel. Expertise is required to decide how many unitsare required, where to locate them and for analysing theresulting data.

5.2.2 Automated activity logging systemsAutomated activity logging systems use a device that istriggered by sound (via a detector) or movement (crossingan infrared beam) and record these as events onto a datalogger or to a camera. Camcorders with a night visionfunction can also be used to record activity and, with the availability of built-in hard disk drive storage,increasingly have the capacity to record for long periodsof time.

Automated activity logging systems differ fromautomated counting systems. Activity logging systemscan be used to derive an index of activity at a location butare not accurate enough to count the number of bats. It isnot possible to determine if the bats being detected orfilmed are different individuals unless the equipment isbeing used at a roost entrance.

Systems that only log activity, but do not record bat calls,will need to be supplemented by further observations orrecordings for identification purposes. However, evenvery simple recording systems can save time bydetermining which areas at a site merit more detailedsurvey work, or which time of the night or season shouldbe the priority for more work.

The restrictions that apply to automated activity loggingsystems are the same as those encountered with the samesort of equipment in any other situation and many factorsneed to be considered when deciding which system to

use. Some systems will be more appropriate for use withcertain species or in particular locations, as some speciesare more easily detected than others and detectors vary intheir sensitivity to different frequency ranges. Thesefactors can be used to advantage in surveys concentratingon a particular species but are a restriction for surveyslooking at the broad spectrum of bat activity.

5.3 Timing, survey effortand frequency Activity loggers can be used at any time of year but lowor negative results obtained when the weather is lessfavourable for bat activity need careful interpretation.During the summer, the system can be used to record batsas they commute, forage, or move to and from daytimeand night-time roosts. During autumn, they can be used toprovide a gauge of the level of swarming activity at a site(see Section 7.3.3). Bats arouse periodically fromhibernation but as activity levels will be lower in winter,bats are most likely to be picked up close to a roostentrance.

Automated systems of both types can be used tosupplement transect survey data by leaving the systemrunning throughout the night when observers are carryingout other surveys nearby.

Using a system of remote detection and bat soundrecording, the numbers of bat passes recorded can varyappreciably from night to night but the overall pattern ofactivity through the night, and the proportions of differentspecies, are likely to be similar on successive nights. It isrecommended that such systems be used in each locationfor three rain-free nights in succession, in order to giverepresentative figures for that time of year. As aminimum, three separate sessions should be carried out ateach location, spaced between May and September, inorder to record seasonal variations in activity. See Table4.7 for frequencies and timings for manual surveys - for sites surveyed both manually and remotely, anintermediate level of survey effort would be required.

Alternatively, programmable automated detectors can beleft to record continuously from mid-May through to mid-September, switching on and off at pre-set times. Thedetector should activate 30 minutes before dusk andswitch off at either midnight or dawn, depending on thesurvey design. The only constraints here are security,the weather and the need to change batteries or link thebattery to a self-charging system such as a solar panel.For example, the equipment could be left to runindefinitely, with only infrequent visits to change batteriesand download data, if the location being surveyed issecure and protected from rain, such as inside a barn or a grilled mine.

In order to correlate results to weather conditions, the useof temperature and humidity data loggers in conjunctionwith the automated systems is required.

5.4 Location of loggersand detectors 5.4.1. Automated detectorsBat activity varies markedly with habitat, so there is aneed to identify the different habitats and structures andto consider their use for roosting, foraging and as flightpaths by different species. Before automated detectors arepositioned, the purpose of the survey must be considered.A few examples of where to site the detector system inorder to suit the survey purpose are given in Table 5.1.

5.4.2. Activity loggersAutomated activity logging is particularly effective wherebats are constrained into a narrow flight path, such asunder bridges or at roost entrances. If the location issecure, the equipment can be left in place over periods ofdays, weeks or even months. The use of such systemsalong flight paths or close to roost entrances can give anindication of the number of bats commuting to or from

the roost, if the time of the observations is recorded. Ifseveral time-linked detectors are used, the direction offlight can also be deduced.

The flight characteristics of the species under study andthe location will need to be considered. A survey of high-flying bats in an open area would require differentplacement of detectors than a survey of activity of a batspecies associated with cluttered habitats. The likelihoodof detecting different groups of bats will need to beincluded in the interpretation of the results.

Automated systems placed in the open can supplementtransect surveys and indicate whether the results arerepresentative of activity at other parts of a large site.

5.5 Sound analysissoftwareThere are several different sound analysis softwarepackages suitable for analysing bat recordings. Twopackages specifically designed for the analysis of batrecordings are BatSound and BatScan; others are general-purpose sound analysis packages (e.g. Spectrogram,Audition [formerly Cool Edit] and WaveSurfer), which

Automated bat activity surveys


Location of detector

On a suitable beam above head height in the barn.

Inside the entrance of a grilled underground site.

In the hedge line at the position of severance.

On a tree facing into the ride.

Detector microphone fixed to wind monitoring mast or balloonto simulate the height of the nacelle.

Purpose of survey

To determine if a barn is used by bats.

To determine if an underground site is used by autumnswarming bats.

To identify commuting activity along a hedge line to besevered by a road proposal.

To determine if a woodland ride is used for foraging.

To determine bat activity in the area of a proposed wind farm(see Box 5.1).

Table 5.1 Examples of locations of bat detector systems according to survey purpose

The significance of any effects of wind turbines on bats in the UK has not yet been determined. Research in the USand in other European countries indicates that wind turbines have a detrimental effect on some bat species,identified as tree-roosting bats, aerial-feeding bats and particularly on migratory bat species. Research is needed inthe UK to determine which species are vulnerable, how significant the effect may be and how it may best bemitigated (for example, by changing the proposed location to avoid important bat areas). It should be rememberedthat development associated with wind farms, e.g. access roads, may have impacts on bats in addition to theturbines themselves.

The methodology for bat activity surveys at wind farm sites is still being developed. It is recommended that anyoneundertaking or assessing surveys for proposed wind farm sites should consult the generic guidelines contained inAnnex 1 to Resolution 5.6 of the Fifth Meeting of Parties to the EUROBATS Agreement www.eurobats.org

Resolution 4.7 of the Fourth Meeting of Parties to the EUROBATS Agreement (also available fromwww.eurobats.org) emphasises that, until research is completed, a precautionary principle should be adopted inrelation to decisions on the development and siting of wind farms, especially along migration routes and in areas ofparticular value to bat populations.

Box 5.1. Note on surveying for wind turbine developments



require more expertise if they are to be customised for batrecordings. The software Analook is designed specificallyfor use with the Anabat system. It does not analyse soundrecordings directly but displays data from a sound wavethat has already been processed in real-time by thehardware.

5.5.1 AnalookSoftware for the analysis of Anabat recordings is suppliedwith the system and kept updated by downloads fromwww.hoarybat.com. There is a full and documentedDOS version of the software but most users now useAnalookW, a Windows-based version. AnalookW is still indevelopment and is not yet documented but it is easy tolearn and notes on its use are available.

The frequency-time displays of bat calls can be shown ata wide range of resolutions. The comprehensive softwareprovides many analysis aids including the facility to labeland annotate recordings. The results – species, time,location and other notes – can be extracted into text files

for importing into spreadsheets in order to perform furtheranalysis, chart plotting, etc.

5.5.2 BatScan and BatSoundBatScan and BatSound both accept sound recordingseither played in via the computer sound card or loadeddirectly as .wav files. They allow the display ofsonograms and power spectra of bat calls, which, togetherwith the measurement of variables, such as pulse lengthand repetition rate, assist in accurately identifying batspecies.

The software of both packages can be used with anyfrequency division or time expansion recordings, althoughthe BatScan default settings have been optimised for usewith the Batbox Duet bat detector. The choice of asoftware package will depend on cost, ease of use,additional analysis aids and the quality of the displays.Demonstration versions of the two packages are availablebut the opinions of existing users should also be sought.

47

6.1 Introduction All bat species resident in the UK have been recordedusing buildings and built structures (e.g. bridges) at sometime during the year. Many also use underground sites ortrees for roosting; surveying these is dealt with inChapters 7 and 8 respectively. Although this chapter dealsmainly with surveys of buildings and built structures,much of the introduction is also of relevance to these laterchapters because it describes roost characteristics andpreferences of different species.

For the purposes of these guidelines the definitions ofbuildings and built structures outlined below have beenused. These are broad definitions that should cover mostcircumstances encountered by bat surveyors.

Buildings Buildings are also structures but they are characterised byhaving walls and a roof. Buildings include residentialproperties, flats, offices, warehouses, garden houses,follies, barns, stables, limekilns, towers, churches, formermilitary pillboxes, schools, hospitals and village halls.Some areas of buildings, in particular cellars, have morefeatures in common with underground sites.

Built structuresA built structure is something that has been man-made butis not a building or an underground site. The mostcommonly surveyed built structures for bats are bridgesand walls but they can also be monuments, statues andchimneys. Within this category are also buildings that arein such a state of disrepair, having lost their roofs, that allthat remains are the walls or part of the walls.

Some species, such as horseshoe bats, are found only inbuildings or underground sites and not in trees. Others,such as the common pipistrelle and brown long-eared bat,are regularly found in a wide variety of built structures,buildings, underground sites and trees. Others, such as thebarbastelle, rely heavily on trees and are onlyoccasionally found in buildings but are regularly recordedin underground sites in winter.

Throughout the year, bats make use of differingenvironmental conditions in various types of roosts inorder to meet the needs of their annual cycle (see Figure3.2 for a diagram of this cycle). At its simplest, maternityroosts need to be warm, whereas winter hibernation sites

need to be cool and humid. Bats occupy these two typesof roost site for significant periods of time but in betweenthese key periods of the year bats will make use of a widerange of other places for shelter and protection.

Bats are usually easier to locate where they occur in highnumbers but will also be found individually or in smallnumbers in locations that cannot be observed directly orappear to be inaccessible to them. In these circumstances,surveying for bats can be very difficult.

As with most ecological survey work there is nosubstitute for practical experience. With greaterexperience comes an improved sense of likely roost siteswithin a building or built structure. However, experiencecan also lead to over-confidence, which can result insome potential roosting locations being dismissed beforeappropriate and thorough survey methods are applied.

This chapter aims to provide guidance on how toapproach and undertake surveys of different types ofbuildings and built structures in order to determine thepresence of bats. The guidance cannot cover all thepossible circumstances that bat surveyors will encounterbut is designed to be adapted to unique or unusual surveysituations.

For information on assessing the need for a bat survey andits planning and preparation refer to Chapters 2 and 3.

6.1.1 Understanding roosts andmaking an assessment of thelikelihood of bats being presentA basic understanding of the different types of roosts usedby bats throughout the year is essential for bat surveyors,as it informs the initial assessment of the likelihood ofbats being present and how a roost survey might beundertaken. General guidance on the preferences ofdifferent species for various types of roosts in the UK canbe helpful and is provided in Table 6.1. This guidance isnot definitive but it illustrates the wide range of placesthat bats can and do use.

Surveyors should also have a good knowledge of thebasic biology of bats and the reasons for selection of


Chapter 6

Surveying buildings and built structures



different roosts at various times of the year. Particularlyimportant is roost use in relation to thermoregulation andenergy conservation.

The use of a building or built structure by bats cansometimes be complex and the bat surveyor shouldalways consider how the building or built structure couldbe used throughout the year. For example, considerationshould be given to determining whether the building orbuilt structure could be used for one or more of thefollowing purposes:

m spring gathering roost that is used by breedingfemales before moving to a maternity roost;

m maternity or nursery roost where females give birthand raise their offspring;

m daytime summer roost used by males and/or non-breeding females;

m mating roost (spring or autumn) occupied by malesseeking to attract females for breeding;

m night roosts used by bats for short periods betweenphases of foraging activity, but rarely or not usedduring the day;

m feeding roost or perch where bats temporarily hangup to devour an item of prey once it has been caught;

m transitional roost used for short periods in the springand autumn;

m pre-emergence flight and foraging area either withinthe same building as the roost or in adjacentbuildings. Such areas are used for a range ofpurposes including warming up, light testing beforeemerging, social interaction and cover frompredation; and/or

m a hibernaculum.

For the purposes of this guidance, summer roost sites

include those occupied from April to September althoughthis also depends on the species, the geographical locationand weather in any particular year. Some will betransitional, especially in the spring (March to May),allowing bats to become torpid during cold weather.

Transitional sites may also allow breeding bats tocongregate before moving to the principal summer roostlocation. Other roosts in late summer and autumn includethose that are formed by males seeking to attract femalesfor mating.

Surveyors should also be aware that species vary in theiruse of summer roosts. For example, some species mayuse a main maternity roost continuously for severalweeks, whilst others may use a number of sites inrotation, often returning to a site more than once duringthe breeding period.

Making an assessment of the likelihood of bats beingpresent will require a level of expert judgement. Forexample, traditional farm buildings and many listedbuildings, especially those close to good foraging habitat,are very likely to be used and will usually require asurvey to determine the presence of bats. Other buildingsor built structures, such as recently built modernindustrial units or inner city structures, particularly ifisolated from foraging habitats, are less likely to supportbats.

Table 6.2 lists some of the features of buildings and builtstructures that surveyors should bear in mind whenassessing the need for, or undertaking, a survey as theywill influence the likelihood of bats, or particular species,being present. Further guidance on assessing the need fora survey is also provided in Section 2.3.



Summer

Often found in relatively modern houses (post-1940s),in confined spaces on external parts of buildings e.g.under lead flashing, in box eaves and cavity walls.Often found in buildings with flat roofs. Also found inolder buildings and built structures such as walls andbridges.

Trees, buildings and bat boxes.

Older buildings with large uncluttered roof spaces.Roost along the ridge beam, in mortise joints, gableends and around chimney breasts.

Old, often stone buildings with large main roof beams,timber-framed buildings and trees. In buildings theylike small crevices such as those between beams or inmortise joints.

Found in a range of buildings, old and new, but dohave a preference for older buildings with stone wallsand slate roofs. Crevice dwellers found under ridgetiles, under slates, behind rafters, hanging tiles androof boarding.

Bridges, especially over water, tree cavities, mill-races,tunnels, mines and cellars. Occasionally in buildings,usually old stone ones. More frequently found withinhouses in Scotland than other parts of the UK.

Woodland species. Roosts in trees and bat boxes.

Primarily a tree dweller. Very rarely in buildings andstructures such as walls. Will use bat boxes.

Tree holes, bat boxes and buildings, both old and new.Found around gable ends, under felt or ridge tiles, andunder loft insulation. Highly mobile species and roostscan be occupied for only a few days.

Typically in 1930s buildings with high gable ends andcavity walls. Also occur in much older buildings andoften in churches. Less frequent in modern buildings.Rarely obvious in the building. Found in cavity walls,crevices, around chimneys, under ridge tiles, betweenfelt and roof tiles or boarding and roof tiles.

Trees and occasionally use of buildings such astimber-framed barns. Rarely found using buildings forbreeding purposes.

Buildings, particularly older ones with a large fly-inaccess point to an open roof. Sites include oldermanor houses, churches and barns.

Larger rural houses, barns and stable blocks offering arange of roof spaces and a nearby cellar, cave, tunnelor ice house where they can go torpid in poorweather. Prefer access with uninterrupted flight, butcan use more inconspicuous gaps if necessary (e.g.under door gaps).

Winter

Small crevices in buildings, trees, stone walls,bridges, barns and also in bat boxes. Often infairly exposed locations to take advantage ofwarmer winter days for feeding. Rarely incaves and tunnels.

Trees, buildings and bat boxes.

Buildings, caves, mines, tunnels and icehouses. Will roost in crevices as well as in theopen.

Cool entrances of caves, mines buildings andother underground structures - even exposedrock face crevices. They will often jamthemselves into crevices.

Caves and tunnels, but also some sites barelyunderground such as follies and limekilns. Incaves they tend to occupy areas close to theentrance.

Caves, mines, buildings and otherunderground sites. Often found in thewarmer, more stable environments. They canbe found closer to the entrance towards theend of winter.

Trees.

Trees, rock fissures, hollows and bat boxes.

Tree holes, crevices in buildings andoccasionally in caves and other undergroundsites.

Thought that most hibernate in buildings.

Buildings, rarely in caves and tunnels.

Caves, disused mines and tunnels, some ofwhich can be 50 km or more from thebreeding roost.

Caves, disused mines and tunnels, some ofwhich can be 50 km or more from thebreeding roost.

Species

Common and sopranopipistrelles

Nathusius’ pipistrelle

Brown and grey long-earedbats

Natterer’s bat

Whiskered/Brandt’s bats

Daubenton’s bat

Bechstein’s bat

Noctule

Leisler’s bat

Serotine

Barbastelle

Greater horseshoe bat

Lesser horseshoe bat

Table 6.1 Examples of places used by bats for shelter and protection



Feature of the building or built structure and its location

Pre 20th century or early 20th century construction2.

Agricultural buildings of traditional brick, stone or timber construction.

Large and complicated roof void with unobstructed flying spaces.

Large (>20 cm) roof timbers with mortise joints, cracks and holes.

Entrances for bats to fly through.

Poorly maintained fabric providing ready access points for bats into roofs, walls,bridges, but at the same time not being too draughty and cool.

Roof warmed by the sun, in particular south facing roofs.

Weatherboarding and/or hanging tiles with gaps.

Undisturbed building roofs and structures.

Bridge structures, follies, aqueducts and viaducts over water and/or wet ground.

For rarer species, building or built structure is located in the core area of thedistribution.

Buildings and built structures in proximity to each other providing a variety of roostingopportunities throughout the year.

Buildings or built structures close to good foraging habitat, in particular mature trees,parkland, woodland or wetland, especially in a rural setting (see Boxes 2.1 and 3.1).

Modern, well maintained buildings3 or built structures that provide few opportunitiesfor access by bats.

Small cluttered roof space.

Buildings and built structures comprised primarily of prefabricated steel and sheetmaterials.

Cool, shaded, light or draughty roof voids.

Roof voids with a dense cover of cobwebs and no sections of clean ridge board.

High level of regular disturbance.

Highly urbanised location with few or no mature trees, parkland, woodland or wetland.

Likelihood of bats being present

Increased likelihood

Decreased likelihood

Table 6.2 Features of buildings and built structures that are considered to influence use by bats in summer1

(adapted from Mitchell-Jones, 2004)

Notes1 This table relates to assessing the potential use of buildings and built structures during the summer. It should be noted that these features may not

necessarily be indicative of use by bats during winter or spring. This table should be read in conjunction with Box 2.1, which provides triggers for batsurveys.

2 Pre-1914 buildings may present the greatest likelihood of providing roost space for bats due to their design, materials used and ageing. Pre-1960 buildings,especially when close to good foraging habitat, and with favoured features such as cavity walls and soffits, can also have a high likelihood of providingroost sites for some bat species.

3 Post-1960 buildings are generally less likely than older buildings to house roosts; however, some modern designs can provide access to suitable roostingspaces for bats. Pipistrelle bats in particular will occupy modern buildings and built structures providing that there are suitable access gaps (> 8 mm) andthat the building or built structure provides appropriate characteristics for roosting. Such situations should be carefully considered.


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6.1.2 Aims of surveyA survey of a building or built structure should aim todetermine:

m if bats are, or have been, present within the buildingor built structure and, if so, which species arepresent;

m the type of roost (e.g. maternity roost, day roost usedby males or non-breeding females, feeding perch,night roost, mating roost, transitional roost,hibernaculum);

m how bats use the building or built structure (e.g.location of roosting bats, flight paths and flightbehaviour, exit and entrance points to the roost); and

m the intensity of use (e.g. number of bats, sex of bats,time and duration of use).

6.2 Methods The aims of the survey, the locations of the bats in thebuilding or built structure and the time of year that thesurvey is being undertaken will all influence the methodemployed.

Survey methods appropriate for buildings and structurescan broadly be categorised as:

m external and internal inspection survey;m dusk emergence survey; m dawn re-entry survey;m netting and trapping survey; andm automated activity survey.

Dusk emergence and dawn re-entry surveys are discussedin detail in Chapter 4 and automated surveys in Chapter5. Methods of trapping bats are discussed in Chapter 9.Surveying for hibernacula at underground sites andautumn swarming surveys are considered in more detailin Chapter 7.

In this chapter, methods for undertaking inspectionsurveys of buildings and built structures are discussed indetail. The use of backtracking and emergence and dawnre-entry surveys, in terms of the effort that may berequired and the approaches that may be employed, arealso considered.

6.2.1 Approach to inspection surveysInspection surveys can be used to determine the actual orlikely presence of bats and how they use a building orbuilt structure. This includes the location of all known orlikely roost sites and evidence of whether they are usedby bats. For many built structures, such as bridges, wallsor buildings where there are no roof voids, internalinspections are not practical and further survey workusing different methods may be required. However, wherepossible, internal inspection of the building or builtstructure should be included.

When assessing a site’s potential as a hibernaculum,surveyors should be aware that bats may hibernate in

places that cannot be accessed through normal surveyingmethods and this may lower the confidence in a negativesurvey result.

To lawfully enter a known roost site, surveyors must be inpossession of an appropriate SNCO licence or beaccompanied by an appropriately licensed person. Fordetails of surveyor licensing, see Section 3.4.

An inspection survey, whether internal or external, shouldbe carried out as follows.

m Permissions should be obtained to enter the buildingand any land with a clear view of the building.Consideration should be given to any equipment(ladders, platforms etc.) required to allow the surveyto be undertaken, especially if entering roof voids.Equipment that may be useful for inspection surveysis given in Box 6.1.

m An appropriate risk assessment should be completedfollowing best practice such as that recommended bythe Health and Safety Executive (see Section 3.5).Internal inspections of buildings in particular canexpose the surveyor to a wide range of hazards, fromfalls to asbestos (see Section 3.5).

m Sufficient time should be allowed during daylighthours to enable a thorough survey to be completed ofall external and internal parts of the building or builtstructure.

m If possible, information should be requested aboutsightings of bats from on-site personnel such assecurity guards, owners of the property orneighbours. However, it should be noted that theobserver may not be objective or may lackexperience, so anecdotal information should betreated with caution.

m The results of the survey should be recorded in astandard manner, for example, on a Bat Roost ReportForm such as that given in Appendix 3 of the BatWorkers’ Manual (Mitchell-Jones and McLeish,2004) including, as a minimum, the informationprovided in Box 6.2. The location of evidence of batusage or potential access or roost sites should benoted on technical elevation and base plan drawingsif these are available; alternatively, drawings of thebuilding or built structure should be made on whichto record the evidence. Correct architectural termsshould be used to describe the different parts of thebuilding; a glossary of terms and diagrams showingthe different structures of roof void is provided inAppendix 1 of the Bat Workers’ Manual (Mitchell-Jones and McLeish, 2004).

m Photographs are often extremely helpful in showingthe structure and condition of a building or forrecording evidence of bat presence, and it isrecommended that digital photographs are taken tosupport written records. Permission may be requiredfrom the building owner to take photographs andcare should be taken to avoid causing disturbance toroosting bats. Where no additional disturbance iscaused, photography without flash is permissible as




an incidental part of licensed conservation orscientific work. Note that the use of flashphotography in roosts or hibernacula requiresseparate licensing (for further details see Mitchell-Jones and McLeish, 2004).

m A search should be made for direct evidence of batpresence. A systematic search pattern should bedeveloped in order to avoid missing parts of thebuilding or built structure. During the survey, asearch should be made for droppings, corpses,scratch marks, urine staining, grease marks and cleancobweb-free gaps around potential entrance pointsand crevice roost sites, including along the ridgebeam. Listen for sounds of bats. Potential accesspoints and roosting sites should be recorded even ifthere is no direct evidence of use by bats. It isrecommended that samples of any droppings arecollected for comparison with a reference collectionor photographic reference material. The inspectionshould be thorough and a consistent search effortapplied to all parts of the building or built structure.It should always be remembered that many buildingsand built structures support more than one roost siteand may be used by more than one species.

6.2.2 EquipmentA list of equipment for undertaking surveys in buildingsor built structures is provided in Box 6.1. It is importantthat surveys are undertaken using the most appropriateequipment in order to provide the necessary health and

safety protection and to minimise the risk of missing batpresence. A range of personal protective equipment (PPE)may be required; this will be determined by the riskassessment and working Method Statement prepared priorto the survey. See Section 3.5 for detailed information onrisk assessments and health and safety.

A powerful torch is required to survey a dark roof void sothat no evidence of bats is missed because of poorillumination. Similarly, a good pair of binoculars isrequired when inspecting buildings or built structuresfrom the ground, in order to view potential features thatmay be used by bats. Without binoculars, there is anincreased risk of failing to see small numbers of batdroppings stuck on walls or window glass on upperstoreys.

Endoscopes and mirrors can be used to look behindfeatures of a building and in mortise joints or cavitywalls, which can provide greater certainty about thepresence of bats. Endoscopes should be used with care -direct contact with bats must be avoided and theendoscope should be slowly and carefully manoeuvred.Furthermore, the close proximity of the light and heatfrom some endoscopes can cause significant disturbanceto roosting bats so they should not be used for longer thanis necessary.

Additional equipment will be needed for an emergence orre-entry survey; Box 6.1 gives details, and further adviceon the use of bat detectors for activity surveys is providedin Chapter 4. Equipment for automated bat surveys isdescribed in more detail in Chapter 5.

Binoculars

Powerful torch to illuminate dark corners from the ground, preferably with a red filter to minimise disturbance to bats

Endoscope and mirrors for inspection behind boarding and in cavities

Small torches for close inspection of cavities and cracks

Spare batteries for torches

Ladders

Access platforms (e.g. scaffold)

Reporting form

Collection pots and labels for corpses and droppings

Elevation and baseline drawings of the building or structure

Camera to record evidence and potential roosting sites

Personal protective equipment (PPE)

Bat detector

Boat to inspect waterside structures such as retaining walls and bridges

Thermometer

Compass

Tape measure or equivalent equipment to measure or make an accurate estimate of the dimensions of the roof void

Clinometer to measure height of building or structure and roost emergence points

Two-way radio

Box 6.1 Equipment for use during inspection surveys of buildings and built structures


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6.2.3 Searching buildings for batsSpecies most often recorded from buildings include:

m common, soprano and Nathusius’ pipistrelles;m brown and grey long-eared bats;m serotines;m greater and lesser horseshoe bats;m Natterer’s bats;m whiskered/Brandt’s bats; andm Daubenton’s bats.

However, it should be noted that barbastelle, Leisler’s,noctule and Bechstein’s bats have also all been recordedin buildings and structures but these occurrences are rarecompared to the species listed above.

For residential, commercial and stone-built agriculturalbuildings, the features that should be given particularattention during an external inspection survey include:

m holes in walls, pipes, gaps behind window frames,lintels and doorways;

m cracks and crevices in stonework and brickwork;m gaps between ridge tiles and ridge and roof tiles,

usually where the mortar has fallen out;m gaps between lintels above doors and windows;m broken or lifted roof tiles;m lifted lead flashing around chimneys, dormer

windows, roof valleys and ridges and hips or wherelead flashing replaces tiles;

m gaps between the eaves, soffit board and outsidewalls;

m gaps behind weatherboarding, hanging tiles andfascia boarding;

m suitable entry and exit points around the eaves,soffits, fascia and barge boarding and under tiles;

m the presence of cavity walls and rubble-filled walls;and

m bat droppings on the ground, ledges, windows, sillsor walls or urine on window sills.

A search should be made of the ground, especially belowpotential access points, windows sills, window panes,walls, hanging tiles, weatherboarding, lead flashing,eaves, behind peeling paintwork or surfacing materialsand under tiles. For buildings constructed from stonerather than brick, particular attention should be paid tocracks and crevices that provide protection from theelements. Such features are known to be used by smallnumbers of bats throughout the summer period andoccasionally maternity roosts have been recorded whereaccess to rubble-filled walls is available.

Once the external inspection has been completed, aninternal inspection should be undertaken. In the case ofderelict or abandoned residential, institutional or officebuildings, bats may be using rooms and other spaceswithin what would have been the living or working space


Evidence of use by bats

Location and number of any live bats.

Location and number of any corpses or skeletons.

Location and number of droppings.

Notes on relative freshness, shape and size of droppings.

Location and quantity of feeding remains.

Location of clean, cobweb-free timbers, crevices and holes.

Location of characteristic staining from urine and/or greasemarks.

Location of known and potential access points to the roost.

Location of the characteristic smell of bats if no other evidenceis recorded

Features of the building or built structure

Type of building.

Age of building.

Aspect of building.

Wall construction, in particular the type of brick or stone usedto build the wall and whether it has cavity or rubble-filledwalls.

Form of the roof, in particular the presence of gable ends,hipped roofs, etc. and the nature and condition of the roofcovering.

Presence of hanging tiles, weatherboarding or other forms ofcladding.

Nature of the eaves, in particular if they are sealed by a soffitor boxed eave and the tightness of the fit to the exteriorwalls.

Presence and condition of lead flashing.

Gaps under eaves, around windows, under tiles, lead flashing,etc.

Presence and type of roof lining.

Presence of roof insulation.

Presence of water tanks in loft (note if covered or uncovered).

Structure of the roof including the truss type, age and natureof timber work.

Information or evidence of work having been undertaken thatcould affect use of the structure by bats.

Box 6.2 Standard information to be recorded in inspection surveys



of the building and each room should be surveyed for batpresence. Surveyors should work quietly and check thebuildings in a systematic manner working upwards fromthe entrance (checking any cellar space last). On enteringan individual level (or room) the places bats are mostlikely to be should be checked first; for example, if thereare droppings under the ridge beam, the area aboveshould be looked at and in open warehouses the darkerareas should be surveyed first.

Within rooms in the buildings, searches should payparticular attention to:

m the floor and surfaces of furniture;m behind pictures, posters, furniture, peeling

paintwork, wallpaper, plaster and boarded-upwindows;

m window shutters and curtains;m wooden panelling;m lintels above doors and windows; andm clean swept floors.

Even where the building is still occupied, an internalinspection of the upper floors is necessary. Closeinspection of window sills and window glass can provideadditional information not clearly seen from an externalsurvey from the ground.

Frequently-used roost locations within roofs include:

m top of gable end walls;m top of ridge and hip beam and other roof beams;m mortise joints;m the junction of roof timbers especially where ridge

and hip beams meet;m top of chimney breasts;m behind purlins; andm between tiles and the roof lining.

A search of the roof void should be made with particularattention paid to:

m all beams for free-hanging bats;m clean swept floors;m droppings beneath the ridge and hip beams of the

roof and junctions between the two;m droppings, urine staining on and at the base of

dividing walls, gable end walls and around chimneybreasts;

m droppings, urine staining and corpses on, under or inmaterials or boxes stored in the roof;

m droppings beneath purlins;m droppings and corpses beneath roof insulation;m corpses at the base of walls and near wall plates at

the base of rafters;m corpses in uncovered water and header tanks or other

containers in the roof;m bat-fly (Nycteribiid) pupal cases19;m scratch marks and characteristic staining from fur oil

on timber and walls;m mortise joints and junctions between roof timbers

and between timbers and walls;m clean gaps and sections of ridge beam and other

timber and walls within the roof;

m gaps between lintels above windows or doors;m light gaps in the roof indicating access points to the

outside; m access to cavity or rubble-filled walls; andm cool areas suitable for torpor or hibernation.

In addition to searching the roof and other parts of thebuilding the surveyor should also listen for batssqueaking and chattering as this can often give away aroost location that is not visible.

6.2.4 Searching bridges for batsBridges require a particular range of knowledge andapproach to surveying to properly assess the presence ofbats. Bats regularly use a wide range of bridges,especially those that cross slow-flowing watercourses orthat are close to good foraging habitat (Billington andNorman, 1997). Species most often recorded from bridgesinclude:

m Daubenton’s bats; m Natterer’s bats;m pipistrelles;m brown long-eared bats;m whiskered/Brandt’s bats; andm occasionally lesser horseshoe bats that are known to

roost in box girder bridges.

Bats roost in many different locations within old and newbridges. Features offering potential include holes, cracksand crevices leading to voids, particularly where there isclear access. Roosting locations in which bats have beenrecorded in bridges include:

m widening joints;m expansion joints;m gaps at the corner of buttresses;m widening gaps (where the width of the bridge has

been increased, forming a gap between the originaland new structure);

m cracks/crevices (usually over 100 mm deep) betweenstonework and brickwork where mortar has fallenout (locations include the underside of the bridgespan and spandrel, parapet and abutment walls);

m drainage pipes and ducts; and m internal voids within box girder bridges.

Access is one of the most difficult issues to address whenundertaking inspection surveys of bridges. There aresignificant hazards to the bat surveyor because bridges areusually associated with roads, watercourses or railwaylines. Where the bridge is over water, a boat may berequired in order to properly inspect the underside of thebridge. If the bridge is tall, lifting equipment orscaffolding may be required in order to undertake adetailed inspection of potential roost sites. If the bridge isover a working railway line, road or canal thenconsideration will need to be given to the specificrequirements and associated risks of working in theseenvironments and work will always need to be agreedwith the appropriate operating authority.

19 A reference for the identification of bat-fly pupal cases is Hutson (1984).


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Once safe and appropriate access has been secured,searches should be made of the ground (especially belowpotential access points) and an inspection made of keyfeatures and locations within the bridge structure that arelikely to support bats.

As with external inspections of buildings, the structureshould be surveyed using binoculars for the presence ofbat droppings, clean gaps, urine staining, scratches,characteristic staining from fur oil, bat-fly (Nycteribiid)pupal cases and droppings. Note that bridges, like trees,can often conceal bats within features that are not visiblefrom the ground.

Where access can be arranged, it is recommended thatpotential or likely roost sites should be inspected closelyusing an endoscope, torch or mirrors. Bridges and wallsdo not usually have accessible areas but where there areinternal voids that can be accessed, they should also besurveyed, following the guidance provided for buildings.

Where there is high potential for bats to be present, but ithas not been possible to confirm bat usage, duskemergence and/or dawn re-entry surveys should beundertaken. It is also known that bridges are often used asnight roosts and for mating and social behaviour. Thesepotential uses should also be accommodated within thesurvey methodology.

It is important to remember that bats may use bridges atalmost any time of the year and timing of any work musttake into account bat activity at each site. It is not unusualfor several bat species to utilise different parts of thesame bridge.

6.2.5 Dusk emergence, dawn re-entry and automated surveys ofbuildings and built structuresFollowing external and/or internal inspection of abuilding or built structure, further survey work in theform of a dusk emergence, dawn re-entry or automatedsurvey may be undertaken to provide additionalinformation on an identified roost or to provide areasonable level of confidence that bats are not present.All three survey approaches can be used to provideadditional information during the summer period, butautomated surveys in combination with inspectionsurveys are likely to be more effective in determiningwinter use. See Chapter 4 for information on duskemergence and dawn re-entry surveys and Chapter 5 forautomated surveys.

Dusk emergence, dawn re-entry or automated surveysmay be required when:

m A roost has been identified and it is important tocollect more information in order to make anassessment of the importance of the roost and thepotential significance of any impacts on it. This mayinclude the number of bats within the colony,determination of access points, species and flightpaths to and from the roost.

m A comprehensive internal inspection survey is notpossible because of restricted access but the buildingor built structure has features that have a reasonablelikelihood of supporting bats.

m A comprehensive inspection survey is not possiblebecause it has been undertaken at a sub-optimal timeof year and there is the risk that evidence of batusage may have been removed by weather, humanactivities or the presence of livestock.

m Inspection surveys have not ruled out the reasonablelikelihood of a roost being present. This decision willbe based on expert judgement but the guidance givenin this document should assist with such decisions.

Night-time bat activity surveys, although not emergencesurveys, can also be useful in identifying summer night-use within buildings.

Dawn re-entry surveys are useful in detecting summerroosts, particularly those used by small numbers of bats,which can be difficult to find especially if they arespecies that emerge late or are seldom detected with a batdetector. It may be easier to see bats re-entering ratherthan emerging, especially if they spend time ‘swarming’around their roost entrance at dawn.

Where it proves difficult to identify a roost entrance forspecies such as brown long-eared bats which emerge latein dark conditions and which do not echolocate loudly, itmay be more effective to locate a surveyor within the roofvoid of a building to watch where bats exit. However, thissurvey should be undertaken with extreme caution as thepresence of a surveyor in the roof may affect the normalbehaviour of the bats. Certainly, no such surveys of thistype should be undertaken between mid-May and mid-July while the females are pregnant or have dependentyoung.

Automated surveys can be very useful in determiningboth summer and winter use of a building or builtstructure especially where other survey techniques areconsidered to be less effective. In this context, automatedsurveys have the advantage of being less intrusive thanmanual ones and can be left ‘surveying’ over a longperiod of time at little additional cost. This is particularlyadvantageous when determining winter use of a building,as bat activity will be irregular throughout the winterperiod.

Automated bat surveys have shown that buildings,especially agricultural buildings, can be used by bats inmost winter months. For example, automated monitoringof bat activity within Paston Barn Special Area ofConservation (SAC) has recorded bat activity at regularintervals through the winter period (English Nature,2003).

6.3 TimingWhere the evidence of bat usage is not exposed to theweather or human interference, surveys for summer roostsin buildings and built structures can be undertaken at anytime, as the signs of roosting bats such as droppings,urine staining, bodies and bones should remain




throughout the year. However, confirming the presence ofbats in locations that are not physically accessible to thesurveyor (e.g. cavity walls or beneath tiles or bargeboarding) or where evidence is removed by rain andwind, is difficult if the bats are not active; in such cases,bats will not be regularly producing fresh evidence oftheir presence or being heard within the roost.

Even in situations where bats roost in the open, evidencemay be removed by cleaners or attempts may be made tohide the presence of bats. Finding droppings in locationssuch as barns with earth floors and buildings used bylivestock is difficult, as droppings may be difficult todifferentiate from the substrate and/or may notaccumulate. Therefore, if there is a reasonable likelihoodof bats, an emergence and/or dawn survey isrecommended in order to provide confidence in anegative survey result.

Emergence or dawn surveys should be undertaken duringthe period that bats are most active (usually April throughto the end of September). The timing of the survey workshould be determined by the surveyor to optimise thelikelihood of recording bats.

It should be remembered that surveys might need to beundertaken in the spring or early summer and again in theautumn to investigate the use of buildings or builtstructures as spring transitional roosts or mating roosts. Atthese times of year, activity may be low due to coolertemperatures or inclement weather, such as high windsand strong rain. Survey days should be chosen carefullyin order to maximise the likelihood of bat activity.

If it is considered that there is a possibility of a maternityroost being present within the building or built structure,the optimum time to undertake emergence or dawn re-entry surveys is judged to be from May to Augustinclusive.

Emergence surveys should begin at least 15 minutesbefore sunset and continue for 2 hours after sunset inorder to take account of all species. For example,Natterer’s, Daubenton’s and brown long-eared bats oftenemerge well after dark. Some species, for example,serotines and pipistrelles, can emerge sooner so an earlierstart time (30 minutes before sunset) may be required.See Table 4.5 for guidance on appropriate start times andsurvey durations.

Dawn re-entry surveys for maternity roosts are often mostsuccessful in August when young bats have only justbegun to fly and their attempts to re-enter the roost areboth obvious and of extended duration; but such surveyscan be useful at any time during the summer. Dawnsurveys should begin at least 90 minutes before sunrise,as Myotis species return to their roost sites much earlierthan other species. See Table 4.5 for guidance onappropriate start times and survey durations.

If a maternity roost is known to be present in a buildingor built structure, access to the roost location during Juneand July should be avoided in order to preventdisturbance to lactating females. At this time an indicationof the size of the roost and the species can be obtainedusing indirect survey methods such as counting and

recording bats as they emerge from the roost.

Following an inspection survey, the surveyor should beable to assess if the built structure has potential to supportbats outside the summer season. If the built structure hasfrost-free areas that can be surveyed either directly, orwith endoscopes or mirrors, then winter or autumnsurveys should also be undertaken between Novemberand March with January and February being the optimumsurvey period (see Chapter 7). Consideration should begiven to the potential level of disturbance that may becaused to hibernating bats by an endoscope and its useshould be kept to a minimum.

Automated surveys in buildings or built structures during the winter period should be undertaken betweenNovember and February.

6.4 Survey effort andfrequencyThe level of effort and the frequency of survey requiredwill vary depending on the type of building or builtstructure under consideration and the likelihood of batsbeing present. Features of buildings and built structuresmost likely to be used by bats are in Table 6.2, but it isnot just these that should inform the decision to undertakea building or built structure survey. The context of abuilding or built structure, sometimes more then thephysical form, will also influence the likelihood of batsbeing present and therefore the level of survey effortrequired. This is discussed further in Sections 2.3 and 3.7.

To illustrate how context can influence an assessment ofthe presence of bats, and thus the survey design, thefollowing scenario is provided by way of example.

A small, modern timber and corrugated metal shed maynot, on its own, appear to be a particularly likely place tofind bats, especially if it supports few features that wouldincrease the chances of bats being present. However, ifsuch a building is located in a wooded valley with fewother buildings nearby and is in the south-west ofEngland, then its potential to be used by bats is likely toincrease. This increased likelihood will require a greatersurvey effort than a similar building located in a lessfavourable place with little or no foraging andcommuting habitat close by. In a poor context, such abuilding may only require a single survey visit but in arich context, such as that described, three survey visitsusing more than one survey method may be requiredduring the main period of activity for bats.

Guidance on the minimum survey effort and frequencyrecommended for buildings and built structures withdiffering potential to support bats is given below. Foremergence surveys, further information is also providedin Chapter 4 and more specifically in Table 4.7.


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6.4.1 General points on survey effortWhere surveys are required of large buildings orcomplexes of buildings, it is recommended that internaland external inspections and/or general activity surveysare completed in advance of emergence and dawn re-entry surveys to help focus survey effort at the mostlikely roost entrances. For large buildings it isrecommended that dawn re-entry surveys should beundertaken as well as emergence surveys.

It should also be noted that the survey design may need tobe significantly altered if it has not been possible toundertake an internal or adequate external inspection. Forexample, access into a roof void or building may beprevented by the presence of asbestos. Under thesecircumstances increased emergence and dawn re-entrysurvey effort should be made in terms of the number ofsurvey visits and the number of surveyors employed onany one survey.

Automated surveys for winter activity within buildings orbuilt structures with a reasonable to high likelihood ofbats being present should be undertaken over a minimumof two weeks per survey. To provide confidence in anegative result, a minimum of two two-week surveysessions should be undertaken during the winter period,with one of these surveys between December andFebruary.

6.4.2 Internal and externalinspection surveysThe time required for internal and external inspectionsurveys will be determined by the number of surveyorsand the complexity of the building or built structure beingsurveyed. Surveys of relatively simple buildings may bestraightforward and quick to complete; however, it takestime to view and understand the roof structure of complexbuildings or groups of buildings. Finding and accessingmultiple entrance points adds time to the survey process.Using a greater number of surveyors should reduce thetime required.

As a guide, typical lengths of time to carry out inspectionsurveys for three different scenarios using a singlesurveyor are given below:

m an internal inspection of the roof area of anunexceptional four bedroom domestic property couldprobably take 1 to 2 hours;

m an internal inspection survey of a traditional timber-framed farm building may take between 1/2 and 1person day; and

m an internal inspection of a large complex buildingsuch as a former hospital or stately home withnumerous roof voids and buildings may take asmuch as 3 to 5 person days to complete.

Inspection surveys for winter roosts can be more timeconsuming, as surveys using endoscopes and mirrors areoften required in order to search for individual or small

groups of bats hidden in crevices.

Time taken for daytime external inspection surveys willalso vary according to the complexity of the building.Evidence may not remain after rain or wind, so weatherand time of year will have a bearing on the level ofconfidence that an external inspection will give.

6.4.3 Dusk emergence, dawn re-entry and automated surveysDetermining an appropriate level of emergence and dawnre-entry survey effort in order to have confidence in anegative survey result is not always a straightforwarddecision. The effort required is a combination of thenumber of survey visits, the number of surveyors andautomated methods employed, the time of season inwhich the survey is undertaken, and the weather at thetime of survey. These factors may also be complicated bythe variety of buildings and built structures involved. Inall cases a level of expert judgement will be required,with such judgements becoming harder as the surveyrequirements and circumstances become morecomplicated. However, the guidance given below isconsidered to represent the minimum level of effortrequired in most circumstances. If, in the expertjudgement of the surveyor, a lesser survey effort isconsidered appropriate, then a clear explanation should bepresented with the findings of the survey.

If the evidence is clear enough, a single daytime surveyvisit may be adequate to determine if bats are, or havebeen, present. However, a negative survey result from asingle daytime visit to a building with moderate or highpotential for bats should be supplemented by additionaldusk/dawn surveys. This is especially important if thedaytime visit has been conducted outside the optimumperiod. A single daytime survey with a negative surveyresult is not considered adequate unless the building orbuilt structure concerned provides no suitable roost sites(i.e. is of low potential, refer to Tables 6.1 and 6.2 forfurther information).

The likelihood of determining the presence of bats isincreased if survey work for summer roosts is undertakenat the optimum time of year and a variety of surveymethods are used.

If bat signs are not present and the building or builtstructure provides no suitable locations for roosting bats,then no further visits would normally be required.However, under these circumstances it is important thatsufficient information is provided to give confidence inthe assessment. It should be noted that a single summervisit will not reveal winter use of a building or builtstructure, although an assessment of the likely use in thewinter may be possible.

If a building or built structure is considered to have a lowlikelihood of use by bats it is considered that one duskemergence survey together with a dawn re-entry orautomated survey is often sufficient to provide confidencein a negative survey result.




If a building or built structure is considered to have amoderate or high likelihood of use by bats, it isrecommended that at least three emergence surveysand/or dawn re-entry or automated surveys per buildingor built structure should be undertaken during the summerperiod in order to give confidence in a negative surveyresult. At least one of these surveys should be a dawn re-entry survey or automated survey. At least two of thesurveys should be completed between mid-May andAugust.

As well as ensuring that the survey includes a sufficientnumbers of visits, the effort in terms of surveyors and/orautomated survey methodologies should also be such thatthere is confidence in the negative survey result. This isperhaps one of the hardest elements of bat survey designon which to provide prescriptive guidance. In general,however, the number of surveyors or automated surveysystems (see Chapter 5) used should be sufficient to coverall likely roost entrances throughout the survey time, inone survey visit or over a number of visits, in order toensure that all likely roost entrances are observed at thefrequency described above.

For example, for a single small simple building such as abungalow it may be possible to undertake an adequatelevel of survey with one surveyor and one or moreautomated survey methods. However, the health andsafety risks associated with lone working at night and theefficacy of an automated survey technique compared to asurveyor should be carefully assessed. Two surveyorswould be preferable.

For larger buildings such as halls, manor houses andinstitutional complexes (schools/hospitals, etc.), a greaternumber of surveyors are likely to be required in order toprovide an appropriate level of survey. Ensure thatsurveyors cover all aspects of a building or built structure.The number of surveyors and automated surveymethodologies should be clearly described in surveyreports illustrating the coverage achieved by the surveydesign.

For large buildings or complexes with a moderate to highlikelihood of bats it may be necessary to increase thenumber of survey visits to more than three and/or increasethe number of surveyors in order to provide sufficientsurvey coverage.

59

7.1 Introduction Bats use underground sites for two main purposes,hibernation and swarming (see section 7.3). Some speciesalso occasionally use underground sites for breeding.

For hibernation, bats require sites that are humid andcool, with stable temperatures and little disturbance. Formore detailed information about roost choice, and thespecies that use underground sites, refer to Table 6.1. Theduration of hibernation depends largely on prevailingweather conditions; bats that might otherwise hibernateabove ground, in hollow trees or crevices in buildings,may enter underground sites during particularly coldspells. Similarly, bats move location within undergroundsites depending on their thermoregulatory needs, and maybe visible or hidden from sight. For example, they maymove from an exposed position near the entrance of acave to a secluded location deep within a crevice, inresponse to a change in ambient temperature.

Some underground sites are used for swarming during thespring and, most importantly, the autumn. This behaviour,which is believed to have a social function, begins inearly August, peaks in mid-August to mid-September andends in October or November, depending on the speciesand geographic location. During this period, many batsmay arrive at the site after dusk, stay for a few hours andthen leave. Therefore, few bats may be present at the siteduring the day.

Daubenton’s bats and greater and lesser horseshoe batshave been recorded breeding in underground sites in theUK. There is, though, the possibility of finding smallnumbers of other species using underground sites as dayroosts during the summer; these are most likely to bemales or non-breeding females. Underground sites maybe used as night roosts at any time of year, especially ifthey are close to good foraging areas. However, theemphasis in this chapter is on surveying for hibernationand swarming sites, reflecting the particular importanceof underground sites for these activities.

In these guidelines, the definition of underground sitesencompasses man-made and natural structures that areentirely or partially underground. They include caves,souterrains, mines, ducts, tunnels, military bunkers, wells,and ice houses. Some underground structures beneathbuildings, such as cellars, are more readily accessible tosurveyors than caves and mines; they are often used aspart of the building, for example, for storage, and may notrequire the same survey approach as for underground

sites. Instead they may require an approach similar to thatdescribed in Chapter 6 for buildings and built structures.

For information on assessing the need for a bat surveyand its planning and preparation, refer to Chapters 2 and 3.

7.2 Surveyingunderground sites forhibernacula7.2.1 Understanding hibernacula andmaking an assessment of thelikelihood of bats being presentIt is essential that bat surveyors have a basicunderstanding of the different types of hibernacula andthe reasons why they are used, as this informs an initialassessment of the likelihood of bats being present andhow the survey should be undertaken. Surveyors shouldalso understand the reasons for roost selection at differenttimes of year, being able to relate this to biology,including thermoregulation and energy conservation.

In these guidelines, hibernacula include those occupiedfrom October to March inclusive. The use of such sitesvaries depending on the species, sexual status, age,geographical location and weather. Some of thesehibernacula are transitional, used when bats are movingbetween summer and winter sites. Transitional sites oftenprovide opportunities for bats to come out of torpor andtake advantage of warmer weather and available preyitems.

The core period of occupancy for significant hibernaculais December to the end of February, when weatherconditions are normally at their harshest. This periodvaries across the UK and may be longer as one movesnorthwards.

The most frequented hibernation sites provide highhumidity and protection from freezing temperatures andwide temperature fluctuations but offer a variety ofenvironmental conditions (such as those found incomplex cave and mine systems) and are close to goodforaging habitat. Conversely, bats are less likely to use


Chapter 7

Surveying underground sites



sites, such as cellars or underground car parks in urbanareas, that have low humidity, temperatures that fluctuatein line with external conditions and are not in closeproximity to foraging areas.

The range of species and the number of bats present at ahibernaculum can vary. Some sites, such as cavity wallsin buildings (see also Chapter 6), may be occupied byvery small numbers of bats (fewer than five) and becompletely inaccessible to surveyors. Other hibernacula,in particular underground sites, can support a variety ofspecies in large numbers. Some species, such ashorseshoe bats, often hang in open situations, whilstothers will squeeze into cracks and fissures, or evenbeneath rubble or stones close to or on the ground.However, horseshoe bats may roost in cavities and otherbats may roost in the open. Some species, in particularbarbastelles and long-eared bats, can tolerate low roostingtemperatures.

Assessing the potential of underground sites to supportbats can be undertaken relatively easily where there issafe access. However, determining the potential bat usageof buildings or built structures by bats in the winter ismuch harder to achieve with a high degree of confidence(see Chapter 6).

Because of their roosting habits, assessing the importanceof a site for horseshoe bats may be easier than for otherspecies, where only a small percentage of the bats presentat a site may actually be visible at the time of the survey.The results of winter surveys in underground sites wherethere are many opportunities for bats to concealthemselves should be interpreted with caution. For thisreason, surveys during the autumn swarming season canbe a useful tool to learn more about the variety andnumbers of species that use a site, particularly thosespecies that may easily be missed during winterhibernation counts (see Section 7.3).

7.2.2 Aims of surveyA winter roost survey of an underground site should aimto determine:

m if bats are, or have been, present within theunderground site and, if so, what species;

m how bats use the underground site (e.g. favouredroosting locations);

m the intensity of use during winter (e.g. number ofbats, time and duration of use); and

m the potential for use of the site by bats in otherseasons (e.g. spring/autumn transitional roost,summer maternity roost or autumn swarming).

The presence of large collections of droppings mayindicate a summer maternity roost but as a general rulewinter surveys are not appropriate for determining use ofa site during the summer and the site should also besurveyed in summer to determine if it is also used at thistime.

7.2.3 Methods PreparationSurveyors entering known hibernacula must be inpossession of an appropriate SNCO licence or beaccompanied by an appropriately licensed person. Fordetails of surveyor licensing see Section 3.4.

It is advisable to consult mining history organisations, theBritish Caving Association (BCA, http://british-caving.org.uk/) or local caving groups beforeundertaking visits to natural caves and abandoned mines.Such organisations frequently have important informationabout safety precautions on or in the site, its layout,history and details of any access agreements. Forexample, the BCA has a Cave Conservation Code(downloadable from their website). These groups mayalso be available to provide training or practicalassistance for survey work, and may even have records ofbat use at the site that could mean further disturbancecould be avoided or reduced.

Each underground site has a particular set of hazards andappropriate training, including Confined Spaces training,may be required, along with specialist equipment (seeSection 7.2.5). Entrances to underground sites may beabove ground level, for example, in quarries or cliff faces,requiring surveyors to have climbing experience andspecialist equipment. No underground site should beentered without conducting a thorough risk assessment,and ensuring that appropriate training has beenundertaken and suitable equipment is available; see alsoSection 3.5.

Undertaking the surveyThe site should be searched systematically from theentrance, with the locations of any bats seen marked on amap or plan of the site. A good torch is essential to lightthe way and to illuminate cracks, crevices and ceilings.Apart from horseshoe bats, which usually hang in opensituations on walls and ceilings of hibernacula, many batspecies are often under-recorded because of their crevice-dwelling habits.

Careful inspection for droppings or oil staining aroundcracks and crevices, including rock piles, may also yieldevidence of use by bats. Activity loggers, which recordbats’ ultrasonic calls over periods of days or weeks, mayalso be used to provide a greater level of survey intensitywith minimal additional effort (see Chapter 5).

The presence of any significant accumulations ofdroppings, Nycteribiid pupal cases20, stained or markedareas should be recorded, as these may indicate thepresence of large numbers of bats during the summer.Further visits during the summer may be required in suchsituations.

Handling hibernating bats has been shown to have adetrimental effect (Speakman et al., 1991) and this mustbe avoided; for most purposes it is not necessary. Whilstit may not be possible to identify individual bats tospecies (particularly some of the Myotis bats), for many

20 A reference for the identification of bat-fly pupal cases is Hutson (1984).

Surveying underground sites

61

surveys it is sufficient to be able to state that bats use thesite and to identify them to genus.

Note that flash photography of hibernating bats should beavoided as the noise and light could disturb them; itwould also require a licence.

7.2.4 Timing and frequencyThe period during which bats will hibernate in any givenwinter is variable and will be influenced by a number offactors, such as the ambient temperature and humidity.Bats can use hibernacula anytime between October andMarch, depending on the weather (see also Table 3.3).The highest numbers of bats in underground hibernaculaare usually found in January.

During the winter, bats move around to sites that presentthe optimum environmental conditions for their age, sexand body weight. Many species are only found inunderground sites when the weather is particularly cold.Bats will periodically arouse to drink, as well as to feed ifit is warm enough for insects to be active – for lesserhorseshoe bats this has been shown to be at temperaturesabove or around 6 - 7° C. Arousal may also be triggeredby disturbance because of increased levels of noise, lightor heat – this may result from the presence of surveyors.The disturbance is not always obvious to the observer atthe time, as bats do not necessarily arouse immediately.There is evidence that the longer the bats have been in atorpid state, the more sensitive they are to arousal stimuli(Thomas, 1995).

Because winter surveys may potentially disturbhibernating bats, visits should be limited to the minimumnecessary to gain the required information. If it isnecessary to assess the numbers of bats using a site, twovisits are recommended, one in mid-January and oneagain in mid-February. BCT’s National Bat MonitoringProgramme hibernation surveys are carried out once inJanuary and once in February. However, if there are verycold temperatures during March, a third visit at this timemay also be considered, especially if this follows a warmwinter when temperatures rarely fell below freezing.Visits should be carried out by a small number of peoplein order to keep disturbance to a minimum and to preventincreases in temperature.

For sites used by more than 10 bats, a single surveyduring cold weather in January or February has a highprobability of detecting at least one bat and therebyconfirming the presence of a hibernaculum. Absence ismore difficult to demonstrate (see Section 7.2.1) and, insome cases, it may be prudent to assume that a suitablesite in good habitat and close to other known roost siteswill be used at some time by bats.

Timing surveys to coincide with a variety of winterweather conditions will provide greater confidence in thesurvey results. The probability of locating bats isinfluenced by the nature of the site as most species,except horseshoe bats, tend to conceal themselves increvices if these are available.

7.2.5 EquipmentSafety equipment is essential when working inunderground sites. Personal protective clothing shouldinclude gloves, warm clothing, protective headgear andfootwear. A basic first aid kit should be carried and it isadvisable to take food and drink when visiting large,complex or remote sites. Other specialist equipment, suchas harnesses, ladders and/or ropes, radon monitoringbadges, gas meters and breathing equipment, may berequired before entering certain unfamiliar or morehazardous caves and mines, and training in the use ofsuch equipment is vital. The BCA may be able to provideinformation about specific sites and on specialistequipment and procedures.

Equipment required for a winter hibernation surveyincludes the following:

m ‘cool’ torch (one producing as little heat as possible)for small sites;

m high power lamp for surveying large caverns;m hard hat with head lamp;m thermometer and humidity gauge to record ambient,

entrance and internal temperatures and humidity;m endoscope and/or mirrors for use in examining

cracks and crevices;m small pot to collect any droppings; andm map or plan, notebook and pen/pencil to record

findings.

7.3 Surveyingunderground sites forswarming activity7.3.1 Understanding swarming sitesThe species composition of swarming bats may be verydifferent from that of hibernating bats found at the site,particularly in areas where most hibernating bats arehorseshoes. Myotis species are most frequently recordedduring swarming activity but may not have been recordedat the site during hibernation (Parsons et al., 2003).Surveys for swarming bats can therefore reveal theimportance of a site for a local or regional population thatcould be missed during hibernation surveys.

The importance of conserving a site that is used both forswarming and for hibernation cannot be over-emphasised.This is because swarming most likely serves a socialfunction and is the mechanism whereby some bat species(in particular the Myotis species) locate mates fromdifferent colonies. This is thought to be important toimprove the genetic mixing of the population and henceits reproductive health or ‘fitness’ (Rivers et al., 2005). Asingle swarming site may serve a population from at leasta 60 km radius around the site.




7.3.2 Aims of surveyA survey during the swarming season should aim todetermine:

m if bats visit a site during the autumn (or spring) forswarming;

m the species or genus of bats present at the site (noteit is not always necessary to identify bats to specieslevel; it may be enough to know that large numbersof Myotis species are present); and

m the intensity of use of the site for swarming (e.g. anindex of activity from automated detectors).

7.3.3 Methods During swarming activity, bats enter and leave a siteregularly during the night so the best place to look forswarming is at the site entrance. Surveyors entering aknown bat roost (swarming sites are often alsohibernation sites), or intending to catch bats, must be inpossession of an appropriate SNCO licence.

Manual detectors, mist nets or harp traps can be used atthe site entrance. Automated detector systems or activityloggers, which record or log bats’ ultrasonic calls overperiods of days or weeks, may be preferable because theyprovide a greater level of survey intensity and are lessinvasive than catching bats. However, these can usuallyonly be used at secure sites, for example, where theequipment can be located behind a locked grille.

Identification of bats to species level is also constrainedwhen using this method and a longer time will be spenton sound analysis (see Chapter 5).

Mist netting and harp trapping are highly invasive andlabour intensive techniques and are more suitable for

detailed scientific studies where identification of Myotisbats to species level is required.

7.3.4 Timing and frequency Surveys for swarming bats are best carried out duringAugust, September and October. Automated recording orlogging systems can be left in place for the duration ofthe swarming season, or even longer, to provide acomparison of the level of activity during swarming withthe rest of the year. Surveys for spring swarming can becarried out in March and April but this time of year is notpreferable as activity is generally far lower than in theautumn.

Bat detector surveys and catching surveys must, ofnecessity, be less intensive than automated surveys,because of the number of people required and thepotential for disturbance. One survey per month betweenAugust and October should be sufficient to identifywhether a site is used by bats for swarming, providedrelatively warm, calm and rain-free evenings are selectedfor surveying. Surveys should begin at 1 hour after sunsetand continue for up to 4 hours.

7.3.5 Equipment To undertake a survey of a swarming site, surveyors mayrequire one or more of the following, depending on theprotocol they determine to be most appropriate (inaddition to the items given in Section 7.2.5):

m manual and/or automated bat detector systems (seeChapters 4 and 5); and/or

m mist net and/or harp traps and associated equipment(e.g. gloves and cloth bags) (see Chapter 9).

63

8.1 IntroductionAll UK bat species rely on trees and woodlands to someextent; they provide valuable foraging areas, shelter fromthe weather and predators and represent key componentsof a connected landscape. However, perhaps the mostsignificant use of trees by bats is as roosts and mostspecies that occur in the UK use trees in this way. Thedynamic ecology of trees and woodland provides adiversity of features that offer bats suitable conditions forroosting throughout the year. For more detailedinformation about roost choice, please refer to Section6.1.

The likelihood of bats being present should be consideredfor all works, from individual tree pruning to large-scaleforestry. Clearly, the survey for an individual tree is notthe same as for a whole forest or woodland. However,there are common principles for identifying features oftrees that are used by bats, including characteristics in thegrowth and decay of the tree and signs of activity left bybats. This chapter will focus on general principles to helpguide arborists and woodland managers in good practicefor their own specific situations, as well as to guideecologists undertaking surveys or providing training andguidance for those undertaking works in trees andwoodlands. It should provide arborists and foresters withthe necessary guidance to: 1. undertake a preliminaryassessment themselves, therefore minimising the risk ofdamage or disturbance; and 2. know when furtherassistance from an ecologist will be required.

Tree works fall into three broad categories, all of whichhave the potential to impact negatively on bats:m Arboriculture (‘tree surgery’) – where the operation

is concerned with a number of individual trees. Thepurpose of the work is to manage the trees forhealth, safety, and aesthetics.

m Forestry and woodland management – where fellingand management works are concerned withpredetermined areas as part of long-termmanagement. This is usually for timber productionalthough other purposes including heritage, amenity,game management, wildlife and recreation may alsoapply.

m Trees and woodlands as part of development projects– where the primary reason for the works is tofacilitate development, for example, construction ofnew housing or roads. Works on trees in this contextare driven by the needs of the development.

As each of these categories of works has distinct and

differing impacts, it is appropriate to consider each theway in which the value of trees for bats should beassessed for each in turn.

Foresters and arborists undertaking their own preliminarybat assessments should have as a minimum basicawareness or training. Bat consultants/ecologists providethe most comprehensive bat surveys and will requirespecific experience of woodland or tree surveytechniques. It is also important to have a basicunderstanding of tree biology and ecology whensurveying trees because relatively minor growthcharacteristics can indicate the presence of decay cavitiesor splits that may not be immediately visible to theinexperienced observer.

Local bat groups who have practical experience and localbat knowledge may be willing to assist woodlandmanagers with surveys. Grant aid may also be availableto survey important bat populations or species forwoodland management purposes.

Because bats are highly mobile, the impact of themanagement of trees and woodlands should be consideredwell in advance of planned works in order to enable areasoned and thorough assessment of any impact to bemade. Failure to do so could lead to significant delaysand/or additional costs.

The long-term and planned nature of woodlandmanagement, which is often laid out in grant applicationsand/or design plans, makes it more realistic to managebats at a landscape scale. This process is described inmore detail in Woodland Management for Bats (ForestryCommission for England and Wales et al., 2005), whichis aimed at those involved in forestry and woodlandmanagement, and describes appropriate survey andmanagement techniques.

The legal protection afforded to bats and their roosts isstrict and good practice is aimed at minimising the risk ofdamage or destruction of tree roosts though it will neverentirely eliminate it. If a tree roost is damaged, it isimportant that consultants, arborists and forest managerscan demonstrate that good practice was followed. It mustbe remembered that roosts are protected even if the batsare not present at the time of any incident. Legalprotection focuses on roost sites but good practice willalso take account of foraging and commuting sites.

For further information on legislation refer to Chapter 1.For information on assessing the need for a bat survey andits planning and preparation refer to Chapters 2 and 3.


Chapter 8

Surveying trees



8.2. MethodsThese guidelines are based on an approach that requiresproportionately more survey effort as the value of thehabitat for bats, and the impact of the loss of that habitat,increases. They are designed to ensure that woodland batpopulations are sustainable, rather than to focus on themanagement of individual tree roosts. By using thisapproach, a workable assessment can be made ofindividual trees (those most likely to be tended to by anarborist), and a proportionate level of effort can be usedto evaluate woodland and forest areas which are morelikely to be managed by a forester, woodland manager oragent. Where removal of trees is planned due todevelopment, it is recommended that each tree is assessedand recorded individually or in discrete groups so thatsurvey and mitigation can be tailored to each feature ofvalue. This is because the loss of a wooded area todevelopment is, in the long-term, markedly different tofelled areas within managed woodland.

The level of survey effort will be dictated by the amountof information required from the survey. The first stage isto establish the features of most value to bats. Thisincludes individual trees with splits, holes or loose barkor groups of older trees in a woodland, where potentialroost sites are more abundant. The value of a particularsite for bats must be taken into account when the impactis considered; this is especially important fordevelopments leading to significant tree loss.

Tree owners/managers should be reminded at an earlystage that trees must not be removed prior to the grantingof planning permission. It is important that bats are notharmed and/or flight lines lost, rendering existing roostsand planned mitigation features redundant.

8.2.1. Preliminary survey – all trees/woodlandsAll trees near to work that is likely to have an impact onbats should have a preliminary visual inspection. Whilstthis survey can be carried out at any time of year, wintersurveys when there are no leaves on the trees will revealmore potential, while summer surveys will be more likelyto reveal signs of activity. In some instances both types ofsurvey may be required.

A preliminary survey should be undertaken as follows:

m Use close-focusing binoculars to inspect tree(s) fromthe ground to the canopy.

m Inspect all aspects of the tree(s).

m Look for features indicative of bat roosts (see Box8.1). Use a high power torch, even in daylight, toinspect cavities and shaded areas of the branchstructure. This is useful at any time but especially soon a dull day. On bright days, it may be necessary totime the surveys so as not to be dazzled by sunlight.

m For surveys undertaken in summer, listen for batsmaking audible social calls from roosts in trees -there is an example on the CD-ROM thataccompanies Woodland Management for Bats(Forestry Commission for England and Wales et al.,2005).

m Ask appropriate people (landowners, managers,wardens, workers or dog walkers) if there is ahistory of bats using the site; be aware this may notbe accurate.

m Record findings on a map. It may also be useful tomark the tree with tape, paint or a tag.

Features of trees used as bat roosts

Natural holes

Woodpecker holes

Cracks/splits in major limbs

Loose bark

Behind dense, thick-stemmed ivy

Hollows/cavities

Within dense epicormic growth

Bird and bat boxes

Signs indicating possible use by bats

Tiny scratches around entry point.

Staining around entry point.

Bat droppings in/around/below entrance.

Audible squeaking at dusk or in warm weather.

Flies around entry point.

Distinctive smell of bats.

Smoothing of surfaces around cavity.

Box 8.1 Common types of features used by bats for roosting and shelter and some field signs that may indicateuse by bats (adapted from the Arboriculture and Bats training course ©BCT/Lantra Awards, 2005).

Tree category anddescription

Category 1 Confirmed bat roosttree with field evidenceof the presence of bats,e.g. droppings, scratchmarks, grease marks orurine staining.

Category 2a Trees that have a highpotential to supportbat roosts

Category 2b Trees with amoderate/low potentialto support bat roosts

Category 3 Trees with negligiblepotential to supportbat roosts

Stage 1 Survey requirements prior to

determination

Tree identified on a map and onthe ground. Further assessment toprovide a best expert judgement onthe likely use of the roost, numbersand species of bat, by analysis ofdroppings or other field evidence.

Ecologist involvement will berequired.

Tree identified on a map and onthe ground. Further assessed toprovide a best expert judgement onthe potential use of suitablecavities, based on the habitatpreferences of bats.

Ecologist involvement may berequired.

None.

Ecologist involvement is unlikelyto be required.

None.

Ecologist involvement will not berequired unless new evidence isfound.

Stage 2 Further measures to inform

mitigation

Avoid disturbance to trees wherepossible1.Further dusk and dawn surveys toestablish more accurately thepresence, species, numbers andtype of roost present, and to informthe requirements for mitigation iffelling is required.

Avoid disturbance to trees wherepossible1.More detailed, off-the-groundvisual assessment Further dusk anddawn surveys to establish thepresence of bats and, if present, thespecies, numbers and type of roostto inform the requirements formitigation if felling is required.

Avoid disturbance to trees wherepossible1.No further surveys.

None.

Stage 3 Likely mitigation

Felled under HabitatsRegulations licence2 followingthe installation of equivalenthabitats as a replacement. Felling would be undertakentaking reasonable avoidancemeasures3 such as ‘soft felling’to minimise the risk of harm toindividual bats.

Trees with confirmed roostsfollowing further survey wouldbe upgraded to Category 1 andfelled under licence as above. Trees with no confirmed roostswould be downgraded toCategory 2b and felled takingreasonable avoidancemeasures3.

Trees would be felled takingreasonable avoidancemeasures3.

No mitigation for batsrequired.

Surveying trees

65

8.2.2 Assessing the value of treesaffected by arboricultural worksBox 8.2 contains a suggested survey protocol for trees due tobe affected by arboricultural works. This method of scoring atree helps to relate the value of a feature to a recommendedaction. The specific criteria within the scoring system areless important than the outcome of each particular score; forexample, High value = needs further inspection/survey whileLow value = proceed with vigilance.

This approach should be considered by arborists as thebasic standard for assessing trees prior to pruning orfelling. For arboricultural operations, an inspection shouldbe made at the earliest opportunity, for example, by anarborist when ‘pricing-up’ a job or undertaking a tree riskassessment. Failure to identify high potential features or

signs of a bat roost could cause considerable delays, ifthese are detected later.

It should be emphasised that when signs of bat use arefound, or where the potential for use remains high aftercloser inspection, then the assistance of an ecologist withappropriate experience should be sought.

Whilst the principle of this assessment method istransferable to all types of bat/tree evaluation, it is notconsidered appropriate for tree works on developmentsites (see instead Section 8.2.4), where more intensivesurvey work is likely to be required in order to assess thevalue of the trees along with other structures at the site,and to determine the impact on flight lines and fromgeneral disturbance over a longer period of time. Surveyeffort should be proportionate to the likely impact of anygiven operation.


Box 8.2 Bat survey protocol for trees due to be affected by arboricultural workThis would consist of a visual assessment of each tree for the likely presence of bats, according to the categories presentedbelow. (Adapted from a protocol provided by SLR Consulting Limited)

Notes1 A general principle for those involved in advising on and undertaking treeworks should be, wherever possible, to avoid disturbance and retain allfeatures which offer some value to bats. For safety-related tree work, abalance should be sought between tree safety standards and the impact onwildlife.

2 When a Habitats Regulations licence to undertake work on a tree roost isrequired, the licence will need to demonstrate that alternative approacheshave been previously considered to try to avoid works to the tree. These may

be options such as diverting paths away from hazardous trees and removingunsafe limbs, instead of felling an entire tree.

3 Reasonable avoidance measures are considered to be good practice. ‘Softfelling’ is a generic term used to describe more cautious felling approaches,using lowering and cushioning techniques to reduce the impact of fellinglimbs which may still have bats within cavities. Where proportionate to theimpact, best practice approaches to felling may include methods such asadditional dusk emergence or dawn re-entry surveys immediately prior tofelling (during the active bat season) or the use of non-return valves toensure that bats can leave but not return to a roost cavity before works begin.



8.2.3 Assessing the value of treesaffected by woodland managementor forestry worksWoodland Management for Bats (Forestry Commissionfor England and Wales et al., 2005) uses an approach thatguides the surveyor towards locating areas of potential forbats, to signal if further survey is required, to locate actualroosts and to identify areas that should be left standing(sometimes known as ‘Natural Reserves’ or ‘MinimumIntervention Areas’). Surveys should be phased, startingwith areas due to be felled, rather than attempting tosurvey all forest blocks within a short timeframe, whichwould be very labour and time intensive.

The survey effort will be determined by the size,characteristics and age of the tree or woodland, its contextin the landscape and the scale of the work proposed inrelation to these features. For example, a brief walkoversurvey may be all that is required for the clearance of ayoung stand of plantation trees that is a small proportionof a large forest that has areas of old growth woodland.On the other hand, a stand of ancient or veteran treesshould have a detailed inspection before any managementworks are carried out. An initial assessment of the areashould be carried out and then survey effort concentratedin areas where a high likelihood of the presence of bats isindicated, preferably surveying twice, once in winterwhen deciduous trees are without leaves, and again insummer when recent signs or sounds of activity may beheard.

It must be emphasised that an experienced ecologistshould be consulted if high potential trees, or actual signsof bat use, are found in areas scheduled for felling orthinning operations.

It is essential that records are made of all surveys toillustrate how the findings have been used to influencemanagement. In addition, this helps to demonstrate thatsteps have been taken to avoid reckless disturbance ordamage.

8.2.4 Assessing the value of trees on development sitesTree works on development sites can have permanent orlong-term impacts on the character of an area and maylimit the opportunities for bats. Examples include loss ofroosts (including maternity roosts, transitional roosts,mating roosts and hibernacula), loss of feeding habitat,impact on commuting routes and lack of shelter fromweather and light. Where this type of work could impacton bats, it is essential that trees on and around thedevelopment site are assessed comprehensively for allfeatures of value. This information will be required toinform the overall mitigation strategy.

Other bat survey work on the site may inevitably havesome overlap with the survey effort required specifically forthe trees. Consequently, suggestions for gauging the amountof survey effort required are provided in Section 8.4.

Where larger areas of woodland may be affected by adevelopment, but not removed altogether, it isrecommended that appropriate advice from WoodlandManagement for Bats (Forestry Commission for Englandand Wales et al., 2005) is used in conjunction with othermitigation measures, for example, identifying rich habitatareas and maintaining minimum intervention areas toensure long-term habitat availability.

8.2.5 Preliminary survey area coverageAll parts of the woodland, or all of the trees in andaround a development or management area, should beinspected. This may require prior arrangement withlandowners, managers or on-site security personnel. Aplan of the woodland or site should be used to guide thesurvey and record the findings. The area to be coveredwill be informed by the initial scoping exercise, and willbe influenced by factors such as the species present in thelocality, the connectivity of a site and the presence ofknown roosts. See Sections 3.6 to 3.8 for moreinformation on desk studies, walkover surveys andscoping exercises.

A particular challenge when surveying trees is to keep theamount of survey effort proportionate to the likely impactof the works being carried out. It is essential that arborists,foresters and other land managers should be able toundertake their own initial assessment with limitedknowledge and training, calling in specialists only wherethe evidence or likelihood of bat presence justifies it.

The inspection of trees, looking for features that could beused by bats, is similar to surveys undertaken forarboricultural reasons. For instance, a tree risk assessmentwill identify decay cavities and branch splits, so existingassessment procedures may be adapted in order toconsider the features in relation to their value as batroosts. Note, however, that these two functions mayconflict, as bats often use the features that make a treehazardous! This can be addressed by training of thepersonnel involved.

8.2.6 Detailed surveyWhere the value of an individual tree or woodland area isfound to be high during a preliminary survey, it isnecessary to undertake a more comprehensive survey ofthe bats present in order to assess the impact of anyproposed management. Should the scope of a potentialimpact change, for example, an increase in the number oftrees to be felled, then further assessment and survey,proportionate to the level of impact, may be necessary.

The scope of additional work will vary considerably,depending on factors such as the habitat type, geographiclocation and altitude.

More advanced survey techniques are likely to include:

m climb-and-inspect assessment of selected trees tocheck for cavities and inspection with an endoscope

or mirrors if appropriate;m dusk and dawn surveys to observe bats leaving and

returning to roosts (see Chapter 4);m back-tracking surveys to follow bats back to roosts at

dawn (see Chapter 4); and/orm automated bat detector surveys to identify

commuting routes and the frequency of bat passes atcertain times (see Chapter 5).

A health and safety risk assessment should always becarried out and safe working methods should be adopted.Climb-and-inspect surveys should be undertaken only bysuitably trained personnel; the use of ropes in trees, and

even using ladders, carries specific risks (see Section 3.5).

Endoscopes can cause disturbance or even harm to batsand there are also limitations of endoscope length. SeeSection 6.2.2 for further discussion on the use ofendoscopes in bat survey work.

All signs of use or potential use by bats should berecorded in a standard manner on a site plan or map. Ifbat droppings are found within or around a tree hole, it isrecommended that a sample is collected for comparisonwith a reference collection.

Pre- and post-parturition (before and after birth)emergence counts may help to confirm whether breedingcolonies are present. Exceptionally, capture may benecessary to confirm species, sex and breeding status orto fit radio-transmitters for further survey work (seeChapters 9 and 10), but these methods must be fullyjustified.

Examples of where advanced survey techniques such asmist netting, harp trapping or radio-tracking may berequired include:

m a proposal with potentially major impacts on a batpopulation, for example, the complete loss of maturesemi-natural woodland;

m a proposal with potential impact on important areasof habitat likely to support woodland specialist batssuch as barbastelles or Bechstein’s bats; or

m a proposal with potential impact on a designated area

(SSSI, SAC, etc.), where bats form part of thespecial interest.

All groups of trees or woodlands exhibiting features ofhigh value to bats should be subject to more detailedsurveys involving night time and roost locating work.This becomes particularly important where plannedfelling will affect older (over 80 years) trees. Wherewoodlands meet the habitat requirements and distributioncriteria for barbastelles and Bechstein’s bats, specialistadvice should be sought, and liaison with the appropriateSNCO is recommended (see Box 8.3).

In some circumstances, where other survey methods areconsidered insufficient or inappropriate, it may beappropriate to undertake precautionary exclusion usingone-way flaps over holes and splits. This helps to ensurethat no bats remain hidden within the tree when it isfelled. However, the legal and licensing implications ofthis should be carefully considered to ensure that the lawis not broken.

8.3 TimingPreliminary visual inspection surveys are best conductedduring winter when trees are leafless and features aremore visible but they can be conducted at other times ofyear if necessary.

The principles of timing for emergence and activitysurveys are common to all survey scenarios. For detailsrefer to Chapter 4. It should be borne in mind that,although bats in woodlands often emerge early, there aresome species that frequently emerge later in the evening.Consequently, night vision equipment will be required toachieve accurate counts and to identify emergence points.

Although bats do fly occasionally in winter, the chance ofan emergence survey taking place on a night when batsare active is small. Therefore a climb-and-inspect surveymay give a better indication of the presence or likelyabsence of bats, if the cavity can be examined to its fullextent.

Surveying trees


Barbastelles may be found throughout most of lowland England and most parts of Wales. They roost primarily in trees all yearround, although occasionally use old buildings such as barns. They normally select ancient or old growth deciduous woodlandswith substantial understorey situated on the headwaters of small undeveloped catchment areas. They move roost site frequentlyand, in consequence, a large number of damaged and dead trees are normally present in favoured woodlands. Roost sites arechiefly in splits or behind loose bark.

Bechstein's bat nursery colonies can be found in central southern England and the southern Welsh borders. Nursery colonies arelocated in old growth or ancient deciduous woodlands of about 50 ha, although smaller blocks of suitable woodlands may beused, if they are well connected. There appears to be a strong tendency to select oak and ash woodlands. Small streams arenormally present in these woodlands. Old woodpecker nest holes are the most frequently selected roost sites.

Should the presence of either of these species be suspected, it is advised that help is sought from ecologists experienced in thesehighly specialised species, and advice sought from the relevant SNCO.

Box 8.3 Barbastelles and Bechstein’s bats



Dawn surveys are useful for detecting roosts in trees,particularly when used by small numbers of bats. Theseroosts can be difficult to find, especially if they are usedby species that emerge late or echolocate quietly and areseldom heard on a bat detector. It is usually easier to seewhere bats enter at dawn, rather than where they emergefrom at dusk. Many bat species spend time at dawnswarming around the roost entrance before entering, sothe entrance points can be easier to locate. For details ofdawn surveys refer to Chapter 4.

For details on the timing of catching and radio-trackingsurveys in woodland, refer to Chapters 9 and 10respectively.

8.4 FrequencyIn a woodland context, it is not possible to state thenumber of surveys that should be undertaken for a givensite. The survey must ensure full coverage of all areasidentified as having potential roosting sites and shouldtake place in suitable weather conditions. If thedevelopment has a defined footprint, it is probably usefulto compare the opportunities offered by the woodland tothose offered by the buildings, and target survey effortaccordingly. For example, a veteran oak tree could becompared to a small barn with thick walls and multiplecracks within timber mortise joints; or a group of 50mature deciduous trees could be compared to a largeVictorian school building with a complex roof structure.This is clearly a subjective judgement so it is essentialthat the amount of survey effort, and the frequency withwhich it is repeated, is justified in relation to known localbat species and bat flight activity around affected areas.

As tree-roosting bats can move roosts frequently,repeating the survey will improve the chance of finding

roosts. However, even very intensive surveys will onlyever find a small proportion of the roosts present inwoodland, so the emphasis should be on identifying andmanaging high value areas. Survey results should betaken as a guide, together with other indicators such astrees with the potential to develop into future roost sites,to gain an understanding of how bats use the habitat.

It is best practice to assume that high potential trees areused by bats at some point during the year or will be inthe future. Mitigation measures can then be providedaccordingly, even if bat use cannot be confirmed and/orthe operation licensed.

8.5 EquipmentThe following equipment is required for a daytimeassessment of trees:

m binoculars - to see into the crown;m bright lamp - which helps to reduce shadow and can

reveal true cavities;m endoscope - may be useful, depending on the type of

survey;m notebook, site map or plan - to record findings; andm access and inspection equipment (ladders or

climbing equipment) - needed for climb-and-inspectsurveys.

Torches and bat detectors are required for nocturnalsurveys both at dusk and dawn. Night vision equipment(video camera or scope) is essential for effectiveemergence surveys of tree roosts; see Chapter 4 fordetails. For details of the equipment required for catchingor radio-tracking bats, see Chapters 9 and 10.

69

9.1 IntroductionMist netting and the use of harp traps to catch bats arewell-established research methods and, as with radio-tracking, they can provide a large amount of detailedinformation in a relatively short space of time. However,because these are invasive methods, it should beconsidered carefully if catching is warranted and theprotocol designed to minimise disturbance. The surveyshould catch the minimum number of bats necessary, anduse the least invasive method appropriate, for the aims tobe achieved.

Where building or land use developments are concerned,the need for catching bats should be based on evidencefrom comprehensive bat detector surveys for bat activity.The evidence should demonstrate that the species andnumbers of bats and the predicted impacts from thedevelopment warrant this intrusive method of surveyingto allow better impact assessment and mitigation design.It would be wise to discuss survey requirements withSNCOs before undertaking such work.

Bats may occasionally need to be caught for the purposeof:

m species identification (where it cannot confidently bedone by a less invasive method - e.g. species that aredifficult to survey using bat detectors, such as brownlong-eared, grey long-eared and Bechstein’s bats);

m sex determination (capture of females may indicatepossible presence of a maternity roost);

m ascertaining breeding status; or m attaching a radio transmitter (if radio-tracking is a

necessary further step in survey, see Chapter 10).

Catching surveys are recommended if it is likely thatproposed work will have a significant impact on batpopulations. For example, if the pre-survey assessment orpreliminary survey identifies potential for Bechstein’sbats, then a catching survey could be undertaken in orderto confirm the species’ presence. It is considered likelythat catching surveys would be required for developmentprojects affecting woodland with high potential for bats,or for works affecting SACs designated for their batinterest.

A specific project licence is normally required for thecapture of bats, and a sufficient level of expertise incapture, handling and identification techniques isrequired. Methods of capture must be specified on alicence application, including the justification for using an

ultrasonic lure, if used, as this may cause additional stressto the bats. Catching surveys should be undertaken byspecialist surveyors with prior demonstrable experienceof the methods to be used (see the Bat Workers’ Manual[Mitchell-Jones and McLeish, 2004]).

For information on assessing the need for a bat surveyand its planning and preparation (including surveyorlicensing) refer to Chapters 2 and 3.

9.2 MethodsBats may be caught in hand nets or cone traps whenemerging from roosts with small entrances, for example,building or tree roosts. For some species, such aspipistrelles and serotines, a hand net may be placeddirectly over the entrance. Some species, such as brownlong-eared bats, can be difficult to catch from outside theroost and these may need to be caught by allowing themto drop into the net from their hanging place within theroost. This method has also been successfully used withgreater horseshoes, Natterer’s and Daubenton’s bats but itmust be carefully considered whether the greater level ofdisturbance inherent with entering the roost is warranted.Harp traps can be used at roosts when bats are exitingfrom multiple points, e.g. pipistrelles emerging frombeneath hanging tiles or weather boarding.

When free flying, bats may be caught with mist nets orharp traps but success will depend on the level of batactivity and the careful siting of the nets or traps. Batdetectors should be used to identify commuting routes.Mist nets are then placed across the routes at dusk inareas where surrounding and overhanging vegetationfunnels them towards the nets. This approach has workedwell for some species, such as barbastelles, greater andlesser horseshoe bats.

Both mist nets and harp traps can be used with anultrasonic lure that is designed to attract bats and increasethe likelihood and rate of their capture. This is a relativelynew technique which should be used with caution bypersons with appropriate training and only where its usecan be justified.

Mist nets and harp traps may also be sited at large roostentrances, for example, the opening of an undergroundsite, to survey for swarming bats (see Section 7.3). Anultrasonic lure would not be necessary in this situation asbats are naturally funnelled toward the net or trap by thesite entrance, and its use may potentially deter bats from


Chapter 9

Catching surveys



entering the site. Mist netting is not advisable for useoutside other sorts of roosts as, if many bats are caught ina short period, extraction from the net may take a longtime and this may result in injury or death. In suchlocations, harp trapping is preferable.

9.3 TimingThe timing of surveys that incorporate the capture of batswill depend on the type of roost or habitat being studied.When catching at roosts, the survey should be timed toavoid catching heavily pregnant females, those that haverecently given birth and are lactating, or those that maybe carrying dependent young. In addition, avoid catchingnewly flying young.

In the field, mist nets or harp traps can be used at anytime of night but will be most successful in the first fewhours after dusk on calm, warm nights during the coreactivity period (see also Table 3.3). As at roosts, it is bestpractice not to catch in foraging habitats or on commutingroutes when females may be heavily pregnant, newlylactating or carrying dependent young. It is difficult togive an exact window during which capture should beavoided, as the time at which bats give birth will varyaccording to the species, latitude and prevailing weather(births will be earlier when there has been an earlyspring). As a loose guide, the period from the end of Mayto mid-July is best avoided, unless there are exceptionalcircumstances where the survey specifically requirescapture during these times.

9.4 Survey effort and frequencyTo identify a species at a roost, capture of one bat on oneoccasion should be sufficient. This may also be the casewhen trying to identify flying bats. However, it may benecessary to capture more than one bat, for example, todetermine sex ratios at a roost or where a minimumnumber is required for radio-tracking. It should be notedthat the ratio of male to female bats at roosts can changethroughout the year and that this has been particularlyrecorded at underground sites.

The minimum number of visits necessary is situation-dependent and also depends on the objectives of thesurvey. A clear picture of the information required fromthe survey should determine the effort required, and whensufficient information has been gathered, work shouldcease.

As an example, on a commuting route already identifiedas being used by bats through bat detector surveys, threenights of catching should be sufficient to catch bats forradio-tracking in order to locate a roost. If the objective isto identify species and/or sex, then one night in goodconditions (not windy or raining) in each active bat month(May-October inclusive) should suffice, especially ifseveral traps are used per km2.

Capture probability can be enhanced by careful selectionof survey sites - see the Bat Workers’ Manual (Mitchell-Jones and McLeish, 2004) for further details. Visitfrequency should be reduced where an ultrasonic lure isused, as this increases the capture probability but also thepotential disturbance. For some species, the use of a lureis more effective in late summer/autumn than at othertimes of the year.

9.5 EquipmentFor more detailed information on methods and equipmentrequired for catching bats, refer to the Bat Workers’Manual (Mitchell-Jones and McLeish, 2004) and Kunz(1988). Information contained in the EUROBATSResolution 4.6 (as amended by Resolution 5.5)21 may alsobe of use. In brief, the equipment that may be required tocatch bats includes the following:

m Hand nets – static butterfly hand nets are used tocapture bats at the roost entrance or inside the roost.

m Cone traps – a net or trap adapted for use at the roostentrance to prevent bats from climbing out. The netmay be left in place for a length of time to capture anumber of bats.

m Mist nets – similar to nets used to catch birds, placedso as to intercept bats in flight. Can be used as batsfly away from the roost, on flight lines withinforaging areas or on commuting routes.

m Harp traps – the costliest of the catching methods but less disturbing to bats than mist nets because thecaptured bats do not become tangled and stressedwhile being removed. Skill is required to set thetension of the harp trap strings correctly.

m Ultrasonic lures, e.g. Sussex Autobat22, have proveneffective at attracting some bats to mist nets and harptraps and hence increasing the capture rate. Thismethod is most appropriate for survey in woodlandwhere bats of several species cannot confidently be separated from one another by bat detector andwhere capture probability of those species thatseldom use woodland rides is otherwise poor. Theuse of lures may also reduce by-catch of otherspecies when a species-specific call is used. It shouldnot be used at or near (within 50 m) roosts as it caninduce high stress levels in some bats and couldcause a roost to be abandoned.


22 The Sussex Autobat was developed by David Hill and Frank Greenaway. For further details see Hill and Greenaway, 2005.

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10.1 IntroductionRadio-tracking is a powerful survey method for locatingroosts, particularly of tree-dwelling bats that are otherwisedifficult to find. It is also useful for determining the typesof foraging areas and commuting routes used by bats froma particular roost or if the bats have alternative roostsnearby. Bats can be caught at, or close to, the roost infeeding or commuting areas, fitted with miniature radio-transmitters, and then tracked as they move to, andbetween, foraging areas or other roosts.

Radio-tracking is an invasive technique that should beused in situations where detailed knowledge is requiredabout a population of bats. Such a technique is unlikely tobe necessary for the majority of development cases butmay be required for a landscape scale development whereHabitats Directive Annex II species or other uncommonbat species are present, or when work may affect a SACor SSSI designated for its bat interest. This level ofsurvey will not normally be required for generalwoodland management unless it will have a high impactand high significance, for example, if Annex II speciescould be present. The need for such surveys should bediscussed with the planning authority and SNCO beforecommissioning any work.

It should be remembered that the individual bats that areradio-tracked comprise only a sample of the wholepopulation and, although detailed information is gainedabout their actual habitat use, they give only an indicationof the type of habitat that the population as a whole uses.The remainder of the population may use other featuresthat the radio-tracked bats did not use. This is especiallythe case for foraging areas, as individual bats usuallyhave discrete foraging areas. Bats that are not radio-tracked may use different commuting routes to reachdifferent foraging areas from those in the radio-trackedsample and the surveyor and client should be mindful ofthis in interpreting the survey results.

The objectives of a radio-tracking survey are likely toinclude:

m determination of detailed species composition andabundance;

m understanding of social and/or community structure; m delineation of home ranges and the ecological

function of the landscape for the species present;

m locating multiple woodland roosts; m delineation of long distance flightlines; orm recording the breeding success of subdivided

colonies.

A survey should provide detailed information on roost,foraging habitat and commuting route use within thelandscape. It may be less useful in terms of estimatinghow bats may use a specific site intended fordevelopment, particularly if the bats largely use areasoutside the site. The aim should be to place the site in thecontext of the overall landscape used by, and the featuresimportant to, the bat population.

The objectives of the survey and the justification for theproposed level of radio-tracking should be clearly statedat the outset and subject to peer review if necessary.

A licence is required for the capture and fitting of batswith radio-transmitters. This type of survey should beundertaken by specialist surveyors with demonstrableradio-tracking experience. A sufficient level of expertisein capture, handling and radio-transmitter attachmenttechniques is required.

For information on assessing the need for a bat surveyand its planning and preparation (including surveyorlicensing) refer to Chapters 2 and 3.

10.2 MethodsFor specific information on capture techniques, and themethods and best practice in attaching radio-transmittersto bats, refer to the Bat Workers’ Manual (Mitchell-Jonesand McLeish, 2004) and Kunz (1988). Informationcontained in EUROBATS Resolution 4.6 (as amended byResolution 5.5)23 may also be of use.

When bats have been radio-tagged, surveyors should aimto locate accurately all roosts of the tagged animals.These guidelines do not attempt to give details of themethodology for locating radio-tagged bats in the field.Reference should be made to other sources (e.g.Kenward, 2000) and knowledge is best gained throughfield experience. Once roosts are located by finding aradio-tagged bat, population sizes and breeding successmay be estimated by emergence counts from the roosts(see Chapter 4).


Chapter 10

Radio-tracking surveys




Surveyors should also aim to identify key foraging areasand commuting routes. This can be achieved by the closeapproach method, where a single bat is followedcontinuously, or the triangulation method, where tworeceivers are used to ‘fix’ the bat’s position. The lattermethod is less accurate but allows more bats to be trackedsimultaneously. The level of resources required to collectthese data can be substantial and, if the objective is tocollect foraging and home range data, this needs fullconsideration in order to justify the tagging of multiplebats. The locations of roosts, foraging areas andcommuting routes can be combined to represent the homerange of a colony.

Careful consideration should be given to the number ofbats used for radio-tracking and the benefits this brings interms of data compared to the welfare considerations forthe bats. In general, more effective results will beachieved with a higher sample size but it is recommendedthat catching of bats to enable radio-tracking should bekept to the minimum necessary to achieve the objectivesof the study. The sample size should be sufficient to gainan overview of the whole colony without having to radio-track every bat. See Section 10.3 for further informationon sample size.

Note that bats can also be marked with chemi-luminescent tags in order to observe hunting behaviour.The tags are short-lived, remaining visible for only amatter of hours. For further information, refer to the BatWorkers’ Manual (Mitchell-Jones and McLeish, 2004).

Note also that ringing of bats is not recommended forsurvey. If several bouts of radio-tracking are anticipated,it may be appropriate to place rings on the bats that aretagged to ensure the same bats are not subsequentlytagged. As individual bats suffer differently from thestress of being radio-tracked, tagging a bat for a secondtime risks inducing unacceptable stress and should beavoided. However, unless there is a specific monitoringobjective or a long-term programme of research, ringing

is not recommended or covered further by theseguidelines.

10.3 Survey effort, timingand frequencyRadio-tracking of one bat of the most appropriatereproductive status and at the most appropriate time ofyear should be used to locate a colony’s roost(s), bearingin mind that many species change roost every few nights.

Radio-tracking of a sample of bats should be used todetermine foraging areas, commuting routes and homerange of a colony (see Box 10.1 for examples).Depending on species, colony size and the intended useof the information, 5-30% of the colony (exceptionally50%) would need to be tracked to have a workingknowledge of the colony territory; 10-15% of the colonymay be sufficient in a colony of 100 or less individualsand 5-10% in a colony numbering more than 100. Itshould not be necessary to track more than a maximum of10-15 bats for any one colony.

In the event that the colony size is not known, forexample, where the roost has to be located first, thisjudgement may only be made once an emergence counthas been conducted to assess the colony size.

In addition, the number of bats to be tracked may beinformed during the survey as the individuals’ homeranges are delineated. When additional data do notsignificantly increase the colony home range (forexample, when expressed as a Minimum ConvexPolygon), then it is likely that enough bats have beentracked in that season. Work on lesser horseshoe colonieshas found that approximately 10 bats were sufficient.Further disturbance by catching and radio-trackingadditional bats can be avoided.

Example 1. Intended clearfell of a woodland block within the territory of a known colony of Bechstein’s bats. Objective is tounderstand how important that woodland block is to the colony and assess the impacts of the intended clearfell. Track 30% of thecolony at low intensity.

Example 2. New road with street lighting cutting across a landscape with probable bat flight lines. All female bats suspected ofbeing from different colonies trapped on the road line are tagged. These animals are followed to locate the roost(s). Then initially5% of the colony is trapped and tagged from the roost. Further tagging may be necessary if it appears that a major problemexists, with up to 30% or more from rare species and important colonies. An alternative would be to obtain a broader picture ofuse by targeting bats using different flight paths or night roosts.

Example 3. Locate an alternative roost when a roost building is to be demolished. One bat is tagged for the life of the tag andlocated each day. When the tag fails it is replaced on a new animal until the colony moves and the new roost is located.

Box 10.1 Examples of radio-tracking survey protocols

Radio-tracking surveys

73

Radio-tracking twice in the year, once in May and againfrom late July and the end of August, will give arepresentation of the behaviour of a colony in differentseasons. The core breeding period of early June to lateJuly, when bats are heavily pregnant or have recentlygiven birth and are lactating, should always be avoidedunless absolutely necessary. In September, bats oftenrange further than in summer and use more roosts,including swarming and hibernation sites. If undergroundsites occur within 10 km of a survey site, tracking may berequired in this month as well.

The maximum survey effort is the lifetime of the radio-transmitter. Given the cost of the radio-transmitter and theinvasive nature of radio-tracking, it is important to gain asmuch information as possible while the transmitter isactive, and to make this available in the form of researchreports or scientific papers in order to furtherunderstanding of the species. Ideally, radio-trackingshould continue until no ‘new’ behaviour is observed.This may be 3, 4, 7 or more nights but extra nights maybe necessary, for example, if bad weather causes a bat toremain torpid for one or more nights. The informationgained should inform the duration for which trackingcontinues.

Minimum survey effort should be three full nights oftracking for each bat. This should be sufficient to meetthe aims of roost location where bats use the same roostrepeatedly, or to gain information solely along a specificflight path. This does not include the first night, as the batmay behave atypically immediately after tagging andrelease. In fact, the data gathered on the first night aftertagging may not be representative and may be discardedat the surveyor’s discretion. If the aims have not been metafter three nights, radio-tracking should continue,especially when tracking tree-dwelling bats that maychange roosts regularly.

To identify foraging areas, commuting routes and homeranges, a minimum of five full nights for each bat is

preferable. It should become clear during the course ofthe radio-tracking survey whether representative datahave been collected. For example, if after several nightsno additional foraging areas or commuting routes arelocated and the home range increases no further.

It is possible to radio-track multiple bats in the samevicinity at the same time, especially if aided by ascanning receiver that enables ease of switching betweenradio frequencies. Alternatively, several radio-trackingteams with separate equipment may be required. Thismay be beneficial where a colony of tree-dwelling batsmay be spread among several tree roosts.

10.4 EquipmentSpecialist radio-tracking equipment is required. In brief,the pieces of equipment required for radio-tracking (inaddition to those needed to capture the bats – see Chapter9) are as follows:

m radio-transmitters and their means of attachment(surgical adhesive24);

m hand-held radio-receivers and antennas (thosemounted on the roof of a vehicle may also beuseful);

m vehicular transport; andm compass, maps and GPS.

It may also be necessary to source computer programmesfor the analysis of radio-tracking data, for example, toenable overlay on habitat maps and calculation of homeranges.

Kenward (2000) and Kunz (1988) are useful sources offurther information on equipment, methods and analysisof data collected through radio-tracking.


24 Note that Skin-Bond® surgical cement, recommended for use in the Bat Workers’Manual (Mitchell-Jones and McLeish, 2004) has changed its formulationand is no longer suitable for use. An alternative, recommended by Holohil Systems Ltd. (see www.holohil.com/bd2att.htm), is Torbot Bonding Cement.



References marked with an asterisk (*) are not cited in thetext but are recommended as useful background reading.

*Altringham, J.D. (1996) Bats: Biology and Behaviour.Oxford University Press, Oxford.

Altringham, J. D. (2003) British Bats. The New NaturalistLibrary, Volume 93. Harper Collins, London.

Barataud, M. (1996) The Inaudible World (2 CD set withbooklet). Edition Sitelle.

Billington, G. E. and Norman, G. M. (1997) TheConservation of Bats in Bridges Project - A Report on theSurvey and Conservation of Bat Roosts in Cumbria.COBIB/English Nature.

Boye, P. and Dietz, M. (2005) Research Report No 661:Development of Good Practice Guidelines for WoodlandManagement for Bats. English Nature, Peterborough.

British Standards Institution (2006) PAS 2010 Planning toHalt the Loss of Biodiversity: Biodiversity ConservationStandards for Planning in the UK - Code of Practice.BSI, London.

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*Hill, J.E. and Smith, J.M. (1984) Bats: A NaturalHistory. British Museum (Natural History), London.

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Kunz, T.H. (Ed.) (1988) Ecological and BehaviouralMethods for the Study of Bats. Smithsonian InstitutionPress, Washington, DC.

*Kunz, T.H. and Fenton, M.B. (Eds) (2003) Bat Ecology.University of Chicago Press, London.

*Kunz, T.H. and Racey, P.A. (Eds) (1998) Bat Biologyand Conservation. Smithsonian Institution Press,Washington DC and London.

Limpens, H.G.J.A. (2005) Vleermuizen en Planologie.Zoogdiervereniging VZZ/Eco Consult and ProjectManagement. The Netherlands.

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Mitchell-Jones, A.J. and McLeish, A.P. (2004) BatWorkers’ Manual. 3rd Edn. Joint Nature ConservationCommittee, Peterborough.

*Mitchell-Jones, A.J., Amori, G., Bogdanowicz, W.,Krysvtufek, B., Reijnders, P.J.H., Spitzenberger, F., Stubbe,M., Thissen, J.B.M., Vohralík, V. and Ziman, J. (1999)The Atlas of European Mammals. T and A D Poyser,London.

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*Neuweiler, G. (2000) The Biology of Bats. OxfordUniversity Press, Oxford.

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Parsons, K.N., Jones, G., Davidson-Watts, I. andGreenaway, F. (2003) Swarming of bats at undergroundsites in Britain - implications for conservation. BiologicalConservation 111: 63-70.

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This Appendix contains information to supplement thatgiven in Chapter 4. It outlines distinguishing features of echolocation calls and flight patterns to assist inidentifying British bats, along with a brief methodologyfor sonogram analysis and references on batidentification.

Echolocation calls and flight patternsThe horseshoe bats are perhaps the easiest to identify to species level, having calls that are both different from vesper bats (all other UK bats are of the familyVespertilionidae hence ‘vesper’; greater and lesserhorseshoe bats belong to the family Rhinolophidae), anddifferent from each other. Their calls are very directionalso, despite being easy to identify, they can be easilymissed. This is particularly the case with lesser horseshoebats. Greater horseshoe bats prefer rough pasture andwoodland edges, and often feed near wet habitats. Theyfly slowly with a fluttering flight and short glides, oftenflying low, even picking up prey from the ground, orambushing prey from a perch. Lesser horseshoes huntover similar ground and are also found in open and closed woodland, with shrub and canopy layers. Lesserhorseshoes fly fairly fast, with fast wing movements. Thisbat species also flies close to the ground; rarely above 5m. Lesser horseshoes often use a night perch to eat theirprey.

Noctules and Leisler’s bats can be distinguished by theircall in an open environment and noctules can be heardover 200 m away. However, both adapt their call to the degree of clutter around them and in a clutteredenvironment are more or less indistinguishable. It helps to see the bat in flight and sound analysis can helpdistinguish between the species if the bats are flying inthe open. Both noctules and Leisler’s bats emerge early,and can be seen flying high, chasing insects, often at thesame time as swifts. Noctules tend to fly higher and makefast turns and steeper dives than Leisler’s bats. Thesespecies are not associated with linear commuting routesas are many other bats. Instead, they circle overwoodland, woodland edge and pasture or above water.They can also be found foraging around white lights. Thenoctule is a larger bat but both have narrow, taperedwings which almost touch beneath the body as they fly.Serotines are almost as large as noctules, but they flymore slowly in large loops at about 6-10 m above theground with occasional dives. Serotines prefer to huntover old pasture, parkland, hedgerows and woodlandedges, but can be seen in gardens and around lights.Serotines have broad wings when compared to noctules orLeisler’s bats and this can make them look bigger,

especially when seen from below. Serotines and Leisler’sbats are often very difficult to distinguish from each otherbased on echolocation calls alone, particularly when theyare in a cluttered habitat. Noctules and serotines alsoshow overlap in call parameters in cluttered habitats.Even with sound analysis these species can be difficult toseparate especially without additional information onhabitat type and behaviour.

Although it is relatively easy to recognise Myotis batsfrom other species, the five members of this genuscurrently found in the UK (Daubenton’s, Natterer’s,whiskered, Brandt’s and Bechstein’s bats [there is only asingle record of greater mouse-eared bat]) are the hardestto separate from each other in the field. They all usesimilar echolocation calls and the more additional fieldinformation gathered the better. Myotis bats, like all otherbats, vary their calls according to the habitat in whichthey are flying, and call parameters overlap most whenthe bat is flying in a cluttered habitat, such as woodland.Sound analysis can assist in the identification of thesespecies; however, it is not sufficiently robust indifferentiating whiskered, Brandt’s and Bechstein’s bats solely from a sonogram. In acoustically clutteredconditions especially, call parameter overlap is often toohigh to attain the degree of certainty required. Moreover,sound analysis on its own is probably not sufficientlyrobust to differentiate any Myotis bats when they areoutside their typical environment; for example,Daubenton’s bats in woodland and Natterer’s bats over a meadow.

Daubenton’s bats are a medium-sized species, takinginsects from close to the water surface or directly fromthe water itself, using their large feet as gaffs or the tailmembrane as a scoop. They have a steady flight, at about25 kph, often within a few centimetres of the watersurface. They can also be found in woodland and alonghedgerows and are more problematic to identify both byecholocation call and flight behaviour when foragingamongst vegetation.

In contrast, Natterer’s bats fly higher over water, about 1 m over the surface. They will use smaller bodies ofwater, with thickly vegetated edges, and hunt over lesscalm water than that preferred by Daubenton’s bats.Natterer’s bats have a tighter ‘turning circle’ and changedirection frequently. They do not tend to fly parallel to thewater surface as do Daubenton’s bats. Natterer’s bats alsohave more abrupt changes in the call rhythm and theircalls are quieter. They also fly in woodland, around treecanopies and other confined spaces, again making tightturns. Natterer’s bats emerge late, often flying close to theroost entrance without emerging until light levels havefallen; this is known as light sampling.

Appendix 1

Identification of bats by echolocation and flight

Appendix 1

77

Whiskered and Brandt’s bats are difficult to distinguish inflight. Both have a rapid agile flight and fairly broadwings and often fly a regular, fixed-height ‘beat’ withtight turns. They both seem to have calls with a slowerrepetition rate than Daubenton’s or Natterer’s bats.

Bechstein’s bats can emerge from their roosts in totaldarkness. They have an apparently fluttering flight but are an extremely agile species. They are woodland batsthat sometimes forage in parks and gardens. They feedalong enclosed vegetation mainly by gleaning, but cantake prey from the ground. Their echolocation call issimilar to the Natterer’s bat though with a larger intervalbetween pulses and a higher end frequency. Bechstein’sbats are frequently missed using traditional bat detectorsurvey methods because their echolocation calls are veryquiet and the bats are often out of range of the detectorespecially when flying in the canopy. The use of acousticlures and radio-tracking have been successful in surveysfor Bechstein’s bats.

Common and soprano pipistrelle bats are reasonably easyto differentiate on a bat detector from each other and alsofrom the more dry sounding ‘clicks’ of the Myotis bats.The flight of pipistrelles appears fast and jerky as theydodge about pursuing insects, which are caught and eatenin flight. Pipistrelles also modify their call parametersslightly in response to the surrounding environment andthere can be some overlap between call characteristics ofNathusius’ pipistrelles in clutter and common pipistrellesin the open. The pipistrelles are the most oftenencountered bats especially in built-up areas.

Nathusius’ pipistrelles usually emerge before the commonand soprano pipistrelles, and their flight is more rapid,less manoeuvrable and with deeper wing beats. They tendto avoid built-up areas more than other pipistrelles, butotherwise use similar habitats. Their calls are also similarbut can be distinguished with practice and sound analysisas they tend to use a lower frequency of maximum energy(peak frequency) and a slower repetition rate. Nathusius’pipistrelles are often found over or around fairly largestanding water bodies.

Long-eared bats are sometimes called whispering batsbecause their calls are so quiet. If sufficiently close, theirhuge ears can sometimes be seen in flight. They oftenfeed in large but enclosed spaces such as barns; they alsouse feeding perches and tend not to feed very far fromtheir roosts. Their calls are louder and of lower frequencyin more open areas and are very distinctive whenrecorded in time expansion for sound analysis. Grey long-eared bats have been reported foraging in bright whitelight.

Barbastelles can be fast flyers and will forage inwoodland, hedgerows, meadows and riverine habitats,depending on the availability of moths, their major foodsource. They have a distinctive two-part echolocation callin most situations and a sonogram can aid identificationof the species.

Sonogram analysis methodologyThis sonogram analysis methodology was originallyproduced for the BCT/MTUK Bats and Roadside

Mammals Survey by Jon Russ.

Sound analysis plays an important part in identifying batsin the field. The methodology presented here foridentifying bats from their calls is based on the analysisof time-expanded recordings using computer software.The methodology does not include the identification ofMyotis and Plecotus bats. The methodology is illustratedthrough BatSound but can be undertaken on other soundanalysis software.

The methodology presented is a general guide to batidentification and should not be used as a precise way ofdetermining individual species. It was originally designedfor large-scale car surveys where the occasional errorwould not affect the overall results. It is also important tonote that the habitat in which an individual bat flies has alarge influence on the shape of its echolocation call andthe wide range of sonogram shapes bats use is clearlyillustrated below.

In order to identify which species the bat call couldbelong to it is necessary to determine the peak frequencyof the call. To do this:

1. Highlight the call in question (see Figure 1 below)and select Analysis-Power Spectrum from thedrop-down menu. (Note: If you cannot highlightanything try right-clicking with the mouse andselecting Marking Cursor.)

2. Move the Marking Cursor so that it hovers overthe highest peak (see Figure 2) (i.e. the one closetto 0 db on the left-hand scale). Then read off thePeak Frequency in the bottom left-hand corner.(Note: Make sure you look at the call only. Thehighest peak, for example, may be at around 10kHz which could be caused by mechanical noise.From the sonogram you should be able to see therange of frequencies covered by the calls [e.g.common pipistrelle sweeps down from about 65kHz to 45 kHz]).

3. Identify which of the categories (A-J) the peakfrequency falls into from the diagram and/or tablein Figure 3.

4. Look at the example sonogram(s) in Figure 4 thatrelate to the categories identified at stage 3 of theprocess. Identify which of the shapes the call beinganalysed most resembles from the sonogram. Forexample, if you obtain a peak frequency of 40kHz, this corresponds to both categories F and G.If looking at the sonograms in F and G the shapemost resembles that of F then the call isNathusius’ pipistrelle.

There may of course be more than one bat present at thesame time. This could be two individuals of the samespecies or two of different species.

There are other calls shapes, including those of socialcalls, which are not included in this key. For moreinformation on bat identification refer to Barataud (1996),Jones and Walsh (2001), Russ (1999), Russo and Jones(2002), Schober and Grimmberger (1997) and Tupinier(1997).




Figure 2. Using the marking cursor to read the peak frequency

Figure 3. Diagram to illustrate the peak frequency ranges ofdifferent call categories, also given in the box at right as a list.

Figure 1. Highlighting a call for peak frequency analysis

Appendix 1


Figure 4. Example sonograms for each of the categoriesA-J illustrating calls of different bat species. Note that the calls represent SINGLE calls emitted by thesespecies isolated from a sequence and NOT a sequence of calls!

Figure 4a Examples of lesser horseshoe (A) and greaterhorseshoe (B) echolocation calls.

Figure 4b Examples of soprano pipistrelle (C),unidentified pipistrelle (D) and common pipistrelle (E)echolocation calls.

Figure 4c Examples of Nathusius’ pipistrelleecholocation calls (F) and barbastelle echolocationcalls (G).

Figure 4e Examples of Leisler’s bat echolocation calls.As calls become more CF and ‘flattened’ (to the rightof the diagram) the more likely it is that theidentification is correct if the peak frequency isaround 23 kHz.

Figure 4f Examples of noctule echolocation calls. Ascalls become more CF and ‘flattened’ (to the right ofthe diagram) the more likely it is that theidentification is correct if the peak frequency isaround 19 kHz.

Figure 4d Examples of serotine echolocation calls. Ascalls become more CF and ‘flattened’ (to the right ofthe diagram) the more likely it is that theidentification is correct if the peak frequency isaround 26 kHz.



The Anabat is an example of a complete system for theremote detection and recording of bat calls. Extensive usehas been made of the Anabat system so some details onits use are provided. Other similar systems are coming onto the market, such as from Stag and Pettersson.

The Anabat hardware consists of a frequency divisiondetector, a real-time analysis and storage module andsoftware (Analook, see Section 5.5.1) for the analysis ofrecordings. The hardware is available as a separatedetector and analysis/storage unit (Anabat II detector andZCAIM CF storage unit) or as a single unit (SD1). A GPSunit can also be connected to the system.

The hardware performs a zero-crossing analysis of thefrequency divided output from the detector and stores theresulting data on a compact flash card; the actual soundsignal is not recorded. The card data are downloaded to acomputer and the bat calls are displayed as frequency-time curves from which the species of bat can usually beidentified.

The Anabat system is particularly suitable for remotemonitoring because of the compact data storage, typicallyone or two megabytes (MB) per night, and the facility torun the system from an external 12V battery. The systemcan be programmed to switch on and off each night, andcan be left unattended for many nights at a time. From thepoint of view of analysis, the Anabat system has asensitivity dial, and when correctly set it will only recordwhen bat calls are detected. Other systems record

continuously, regardless of bat calls, involving thesurveyor taking time to go through many hours of‘silence’ during sound analysis.

Other systems can be put together using existinghardware; for example, the University of Leeds have used a system with a Batbox III, sensitive, low noiseheterodyne detector and a Skye counter which counts bat passes by triggering on the first call of a pass and de-activating for pre-set time (e.g. 0.5 s) so as not tocount each bat more than once. The cumulative numberof calls is output to an external logger. A lead-acidrechargeable battery (12V, 4Ah = 7 days) powers theBatbox III, which is the component that limits the timethe system can be left unattended. A waterproof caseholds the entire system with an 11 mm diameter holedrilled into the case in front of the detector’s microphone.Since it is tuned to a single narrow frequency bandwidth,it will not detect all species. For further information, seeGlover and Altringham (2007).

In addition to heterodyne systems, a Batbox Duet infrequency division mode has been used to monitor greaterand lesser horseshoe bats with a minidisk recorder forovernight recording (Glover and Altringham, 2007). Also,Pettersson D240x time expansion detectors have beenconnected to VOR walkman/Dictaphone/MP3 recorderswhich provide very good recording quality, althoughbattery lifespan is short (1 night) (P. Reason and D. Wellspers. comms.)

Appendix 2

Automated bat detector systems

Apendices 3 & 4


ALGE Association of Local Government Ecologists

BCT Bat Conservation TrustCBD Convention on Biological DiversityCCW Countryside Council for WalesCEnv Chartered EnvironmentalistCITB Construction Industries Training BoardDefra Department for the Environment, Food and

Rural AffairsDoENI Department of the Environment Northern

IrelandEA Environment AgencyEHS Environment and Heritage Service

(Northern Ireland)EN English Nature (now Natural England)EPS European Protected SpeciesFCS Favourable Conservation StatusHPA Health Protection AgencyHSE Health and Safety ExecutiveIEEM Institute of Ecology and Environmental

ManagementNE Natural England (formerly English Nature)

NERC Natural Environment and Rural Communities (Act)

NNR National Nature ReserveNPPG National Planning Policy Guidance

(Scotland)PAN Planning Advice Note (Scotland)PPE Personal Protective EquipmentPPS Planning Policy Statement (England)SAC Special Area of ConservationSE Scottish ExecutiveSEERAD Scottish Executive Environment and Rural

Affairs DepartmentSEPA Scottish Environment Protection AgencySI Statutory InstrumentSNCO Statutory Nature Conservation OrganisationSNH Scottish Natural HeritageSR Statutory RuleSSSI Site of Special Scientific InterestTAN Technical Advice Note (Wales)VTA Visual Tree AssessmentWAG Welsh Assembly Government

Appendix 4

List of abbreviations used

Autumnal swarming Bats gathering in flight at an underground site in autumn Dawn swarming Bats gathering in flight outside a roost before and during sunriseDay roost Site where one or more bats spend the dayFeeding perch A place where a bat hangs while detecting prey or consuming itHibernaculum A winter site where the bats enter torpor during hibernationMaternity roost A breeding roost where mothers give birth to, and care for, their youngNight roost A site where bats rest, groom etc. between bouts of foragingNursery roost As maternity roostPre-lactation The state of a female before producing milk for sucklingPost-lactation The state of a female after producing milk for sucklingPre-parturition The state of a female before giving birthPost-parturition The state of a female after giving birthRoost A resting place of a batSatellite roost A smaller roost than a maternity roost but nearbySwarming Bats gathering outside a roost at dawn or in autumnTorpor Slowing the metabolic rate and entering a state of deep sleepTransitional roost An occasional roosting site usually used in spring and autumn before and after using a

maternity roostVolant Able to fly

Appendix 3

Glossary of bat terms



Organisations and government departmentsBat Conservation International www.batcon.org Bat Conservation Ireland www.batconservationireland.org Bat Conservation Trust www.bats.org.uk British Caving Association http://british-caving.org.uk/ Countryside Council for Wales www.ccw.gov.uk Defra www.defra.gov.uk Department of Environment Northern Ireland www.doeni.gov.uk Environment Agency www.environment-agency.gov.uk EUROBATS Agreement www.eurobats.org Health and Safety Executive www.hse.gov.uk Highways Agency www.highways.gov.uk Institute for Ecology and Environmental Management www.ieem.net Joint Nature Conservation Committee www.jncc.gov.ukNational Biodiversity Network www.searchnbn.net National Federation for Biological Recording www.nfbr.org.uk Natural England www.naturalengland.org.uk Office of Public Sector Information www.opsi.gov.uk Scottish Natural Heritage www.snh.org.uk Scottish Environment Protection Agency www.sepa.org.uk The Mammal Society www.abdn.ac.uk/mammal/ The Wildlife Trusts www.wildlifetrusts.orgUK Biodiversity Action Plan website www.ukbap.org.uk

Book SuppliersAbebooks (for out of print books) www.abebooks.com Alana Ecology www.alanaecology.co.uk Amazon www.amazon.co.uk Natural History Book Service www.nhbs.com Speleobooks www.speleobooks.com

Appendix 5

Useful websites


The Bat Conservation Trust (BCT) is the only nationalorganisation soley devoted to the conservation of batsand their habitats in the UK. BCT’s vision is a world

where bats and people live in harmony, and it isworking to ensure these amazing mammals are around

for future generations to enjoy.

Bat Helpline: 0845 1300 228www.bats.org.uk

The printing of this publication has been sponsored by

SDPNT Poe 2.9 – Distribution Atlas Of Bats In Britain And Ireland

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