HEDGE ASSESSMENT AND BAT ACTIVITY SURVEY · 4.2 Bat Activity Survey One bat activity survey was conducted at the site, as described in section 3.2. The raw data from this survey are

HEDGE ASSESSMENT AND

BAT ACTIVITY SURVEY

Brook Farm

Marden

Herefordshire HR1 3ET

Final report 20th August 2013

Survey and reporting: Dr Johnny Birks BSc MCIEEM

NE Bat licence WML-CL18 (v 01/2013)

Checked by: Lisa Kerslake BSc MSc CEnv MCIEEM

Client: S & A Produce Ltd.

© Swift Ecology Ltd

Rose Cottage

Market Square

Kineton

Warwick

CV35 0LP

Tel 01926 642541

Email [email protected]

Website www.swiftecology.co.uk

Printed on recycled paper

Hedge Assessment and Bat Activity Survey SWIFT ECOLOGY

C998 Brook Farm, Marden, Herefordshire 1

CONTENTS

1 SUMMARY ................................................................................................................................... 2

2 INTRODUCTION................................................................................................................................. 3

2.1 BACKGROUND ................................................................................................................................ 3 2.2 ECOLOGICAL CONTEXT ..................................................................................................................... 3

3 METHODS ................................................................................................................................... 4

3.1 HEDGE ASSESSMENT ........................................................................................................................ 4 3.2 BAT ACTIVITY SURVEY ...................................................................................................................... 4 3.3 CONSTRAINTS ................................................................................................................................. 5

4 RESULTS ................................................................................................................................... 6

4.1 HEDGE ASSESSMENT ........................................................................................................................ 6 4.2 BAT ACTIVITY SURVEY ...................................................................................................................... 6

5 EVALUATION ................................................................................................................................... 8

5.1 EVALUATION OF HEDGE AGAINST WILDLIFE SITE CRITERIA ....................................................................... 8 5.2 BATS ............................................................................................................................................. 9

6 RECOMMENDATIONS ................................................................................................................... 11

6.1 PRECAUTIONARY APPROACHES TO DEMOLITION/REMOVAL WORKS ........................................................ 11 6.1.1 Bats ................................................................................................................................. 11 6.1.2 Nesting Birds ................................................................................................................... 11

6.2 HABITAT COMPENSATION AND BIODIVERSITY ENHANCEMENT MEASURES ................................................ 11

7 RELEVANT LITERATURE ................................................................................................................. 13

APPENDIX 1 HABITAT COMPENSATION AND ENHANCEMENT MEASURES.................................. 14



1 SUMMARY

• A section of roadside hedge was assessed for its biodiversity value and a bat

activity survey at dusk was undertaken at Brook Farm, Marden in July 2013.

• This ecological work was required in connection with proposals to remove a

section of the hedge and to demolish or remove some of the buildings with

low bat roosting potential on the site, prior to constructing a new vehicular

access and a new office building.

• The habitats and plant species found in the hedge section are widespread

and common, and its botanical diversity is relatively low. The loss of this

section will have a minor, short-term adverse effect upon biodiversity in the

locality.

• Levels of bat activity on the site were low during the dusk survey, and there

was no evidence of bats making use of the buildings proposed for demolition

or removal.

• This low level of bat activity and the low bat species diversity at the site is

consistent with the relatively poor bat foraging habitat present and the low

bat roosting potential of the buildings on the site.

• The majority of bat activity and the greatest species diversity (albeit both

rather limited) was associated with the southern edge of the site, where a

line of trees provides both foraging habitat and a commuting route. This line

of trees will be removed as part of the proposed development, so there will

be some impact upon bats as a consequence.

• Overall, the proposed changes to the site will have a minor adverse impact

upon bat activity in the locality.

• Any adverse effects will be short-term only, because compensatory habitat

creation will lead to a significant increase in biodiversity on the site; this will

include an increase in the availability of foraging and commuting habitat for

bats on the site.

• Detailed recommendations are made for biodiversity enhancement through

compensatory habitat creation.



2 INTRODUCTION

2.1 Background

A length of roadside hedge at Brook Farm, Marden was assessed to determine its

ecological value and a bat activity survey was conducted around the farm buildings;

both were undertaken in connection with proposals to remove a section of the

hedge and to demolish some barns and portacabins prior to construction of a new

office building. Because the buildings to be demolished or removed have very low

potential to support roosting bats, no further assessment of roosting activity was

required. The hedge assessment and activity survey were carried out by Swift

Ecology on 11th July 2013. The site is located at approximate OS grid ref. SO521482.

2.2 Ecological Context

Brook Farm is situated in a rural setting just north of the village of Marden in central

Herefordshire (Plate 1). The site surveyed comprises a mix of large modern fruit

processing buildings with some older barns and temporary office accommodation

including several portacabins (Plate 2). The site is surrounded by farmed

countryside, which is dominated by grassland and some arable to the west, and by

soft fruit production under polythene to the east. The meandering, tree-lined River

Lugg lies 400 m to the west; immediately to the south is an area of accommodation

for seasonal workers on the fruit farm with some recreational facilities; there are

clumps and lines of trees close to an old farmhouse visible in Plate 2; areas of low

density housing in Marden lie 300 m to the south. There are some hedgerows and

scrub bordering the Brook Farm site, but there are no large woodlands within 2 km

of the site. These habitats provide some opportunities for foraging and/or roosting

bats.

Plate 1. Google Earth image showing the landscape context of Brook Farm, Marden.

The approximate area surveyed for bats is identified by a yellow outline.



3 METHODS

3.1 Hedge Assessment

The structure and species composition of the hedge and its associated ground flora

were assessed on the 11th July 2013. This assessment focused on the section

proposed for removal (shown in Plate 2). Notes of evidence of other wildlife species

were made. An evaluation of the effects of removal of the section of hedge was

made against key wildlife site criteria.

Plate 2. Google Earth image of the Brook Farm site, showing the locations of the

roadside hedge assessed (red line identified by red arrow) and the ten stations

occupied in sequence during the bat activity survey (yellow numbers); the two barns

assessed internally for signs of bat activity are identified by red triangles.

3.2 Bat Activity Survey

A single bat activity survey was carried out at dusk on 11th July 2013. A single

surveyor moved between ten pre-selected stations in sequence to record bat activity

for periods of five minutes at each station. The locations of these stations were

chosen to provide good coverage of the areas to be affected by the proposed

development; two of the stations were located beside the hedge proposed for

removal (see Plate 2). Each station was monitored at least twice during the survey

period of approximately two hours and twenty minutes. The surveyor also recorded

bat sounds while walking between stations.

During each circuit of the stations, the interiors of two barns proposed for

demolition were checked for signs of bat activity using bat detectors and a powerful

torch (these barns are identified in Plate 2). The western-most barn is open at its

eastern end and recording station 1 was located at this eastern end; the eastern



barn is normally kept closed and has been adapted for social events, so opportunities

for bat access and roosting are more limited.

Two ultrasonic bat detectors were used to detect and record bat calls; these

included an Anabat system. A digital recording device was connected to a manual

bat detector to store bat echolocation calls for subsequent analysis using Batsound

software. The bat activity survey approach was based upon the Good Practice

Guidelines for manual bat surveys (Hundt, 2012). Details of personnel, equipment,

timings and weather conditions are given in Table 1.

Table 1: Brook Farm, Marden Bat Activity Survey Details

Survey type Dusk

Date 11 July 2013

Weather conditions Dry, calm and clear sky after a warm day. Start temp. 20 oC; finish 13 oC

Sunset

/sunrise time (BST)

2129

Start time 2114

End time 2335

Personnel Johnny Birks

Equipment 1 x Pettersson D240x, 1 x Anabat

3.3 Constraints

July is a reasonable month for assessing the botanical interest of hedges because

many characteristic species are identifiable then. The bat activity survey was carried

out in reasonable weather conditions.



4 RESULTS

4.1 Hedge Assessment

The section of hedge that will be affected by the proposed development comprises

an approximately 30 m length that runs north to south between the Brook Farm site

and the minor road that leads north from the village of Marden towards Bodenham.

The hedge has been managed by standard trimming methods; at its maximum it is

approximately 3 m high and 1-2 m wide at the base. A small drainage ditch runs

along the roadside of the hedge for the majority of its length; at its southern end this

ditch is piped and runs underground.

Along the majority of its length the hedge is composed of a limited range of native

broadleaved shrub species dominated by elm Ulmus sp. (probably English elm Ulmus

procera) and hawthorn Crataegus monogyna, with field maple Acer campestre

occasionally present. At its southern end the hedge is less natural in character, with

Leylandii the dominant woody species and a single pedunculate oak Quercus robur

present; this less natural part of the hedge extends for about 10 m and is bordered

by a 1.5 m high dilapidated larch-lap fence on the roadside.

The more natural sections of the hedge are characterised by a range of climbing

plants including cleavers Galium aparine, hop Humulus lupulus, ivy Hedera helix,

bramble Rubus fruticosus and bittersweet Solanum dulcamara; in the less natural

section of the hedge, of these climbers, only ivy is sparsely present.

The ground flora beneath the hedge comprises a limited range of common wayside

flowers such as hedge woundwort Stachys sylvatica, white dead-nettle Lamium

album and black medick Medicago lupulina; coarse grasses such as cock’s foot

Dactylis glomerata; and ruderal plants such as nettle Urtica dioica, dock Rumex sp.,

spear thistle Cirsium vulgare and creeping thistle Cirsium arvense.

4.2 Bat Activity Survey

One bat activity survey was conducted at the site, as described in section 3.2.

The raw data from this survey are presented in Table 2, and the main findings are

summarised below.

Although bat activity was recorded at nine of the ten stations during the survey, the

level of bat activity was generally very low and only three bat species were recorded:

common pipistrelles Pipistrellus pipistrellus were recorded most frequently and most

widely (at eight of the ten recording stations); soprano pipistrelles Pipistrellus

pygmaeus were recorded twice at station 2 only; and noctules Nyctalus noctula were

recorded twice, once each at stations 4 and 5.

Most bat activity and the greatest bat species diversity (albeit very limited) were

recorded at stations on or close to the line of trees on the southern edge of the site.



Very little bat activity was recorded at stations 8 and 9 beside the roadside hedge

proposed for removal.

No bats were observed or recorded inside either of the two barns subject to internal

checks (each barn was checked on three separate occasions, as indicated in Table 2

below).

Table 2: Bat activity survey results from the Brook Farm site on 11th July 2013.

Station

no.

Timing

of visits

(BST)

Activity/comments

1 (east

end of

barn)

2114-19 No bat activity


2314-19 2318 - Faint pass by common pipistrelle over barn

Note barn interior was checked for bats during each of the periods above

2 2120-25 No bat activity


2320-25 2320-23 - Several foraging passes by common pipistrelles near trees to south of

station 2


2224-29 2225 – Foraging pass by common pipistrelle along line of conifers

2325-30 2325 and 2329 – Passes by soprano pipistrelle

2326-2330 – Several passes by common pipistrelles along tree line.

Internal checks of eastern barn at 2130 (no bats), 2230 (no bats) and 2331 (no bats)


2231-36 2231 – Pass by noctule overhead


2236-41 2236 – Pass by noctule

2240 – Brief, faint pass by common pipistrelle


2244-49 2244 – Common pipistrelle feeding around security light?


2249-54 2249 – Common pipistrelle pass

8 2153-58

2254-59 2255 and 2257 – Passes by common pipistrelle along hedge line

9 2158-

2203

No bat activity

2259-

2304

No bat activity


2304-09 2305 and 2308 – Passes by common pipistrelle



5 EVALUATION

5.1 Evaluation of Hedge against Wildlife Site Criteria

The section of hedge proposed for removal is assessed as follows against standard

Wildlife Site Criteria:

• Diversity

The hedge section is not very diverse; relatively few species are present.

• Rarity

No rare species were in evidence, and habitats present are common in a county

context. However, the presence of English elm is of some value as a species that

has declined in past decades.

• Size

The area of the hedge section is small (< 100 m2) although it is contiguous with a

longer stretch of hedge and other tree and shrub cover.

• Naturalness

The hedge section is a man-made feature, albeit mainly composed of native

species, which has been subject to frequent management to maintain its current

form. Therefore, its naturalness is relatively low.

• Fragility

The hedge section has been managed frequently, is located adjacent to a road,

and therefore is not particularly fragile.

• Typicalness

Because of the effects of management, the hedge section is unlikely to represent

a very typical example of any particular habitat other than roadside hedges.

• Ecological position

The hedge section is an integral part of a longer stretch of hedge in an area

where the abundance of tree and shrub cover and wildlife corridors is relatively

limited because of the open character of the agricultural landscape. The hedge

may be used as a dispersal route by certain scarce species such as dormouse

Muscardinus avellanarius. Therefore, the hedge section’s position as a linking

part of a corridor is of some importance.

• Significant populations of species

The hedge section is unlikely to support significant populations of any wildlife

species. However, it is likely to support small populations of certain species,

including nesting birds.



• Potential value

The value of the hedge section could be enhanced by appropriate management,

such as a reduced frequency of cutting.

• Physical and visual access

A road runs adjacent to the hedge section. There is no public access on its

eastern side.

• Educational value

The hedge section is unlikely to have significant value as an educational resource.

• Community and amenity value

Not known but probably limited.

• Aesthetic appeal and landscape character

The hedge section has limited aesthetic appeal or landscape character.

• Geographical position

The hedge section lies to the north of the village of Marden.

• Recorded history

This is not known, though the low shrub diversity suggests that the hedge is not

of a great age.

• Continuity of land use

The hedge section has had some continuity of land use due to its persistence as a

roadside feature.

In summary, the habitats and plant species found on the hedge section are generally

widespread and common. In view of this assessment and the relatively short length

of hedge proposed for removal, the loss of this section will have a minor, short-term

adverse effect upon biodiversity in the locality. In the longer term, there will be

significant net biodiversity gains as a consequence of compensatory habitat creation

on the site as part of this development.

5.2 Bats

Levels of bat activity on the site were low during the dusk survey, and there was no

evidence of bats making use of the two barns that were checked internally. This low

level of bat activity and the low bat species diversity at the site is consistent with the

relatively poor bat foraging habitat present (little or no vegetation is present within

the site to support insect prey) and the low bat roosting potential of the buildings

(relatively modern structures built of materials other than timber and stone that are

not normally favoured by roosting bats) on the site.

The low level of bat activity along the roadside hedge proposed for removal suggests

that it is neither a significant foraging habitat nor commuting route for bats.



The majority of bat activity and the greatest species diversity (albeit both rather

limited) was associated with the southern edge of the site, where a line of trees

provides both foraging habitat and a commuting route. This line of trees will be

removed as part of the proposed development, so there will be some impact upon

bats as a consequence.

Overall, the proposed changes to the site (removal of the roadside hedge on the

western boundary and trees along the southern boundary, and demolition or

removal of buildings and construction of a new office building) will have a minor

adverse impact upon bat activity in the locality. However, this will be a relatively

short-term effect because compensatory habitat creation will lead to a significant

increase in the availability of foraging and commuting habitat for bats on the site.



6 RECOMMENDATIONS

6.1 Precautionary Approaches to Demolition/Removal Works

6.1.1 Bats

Given the lack of evidence of any use of the buildings by bats, and their very low

suitability for roosting bats, it is unlikely that there will be any impact on bats or bat

roosts as a result of the demolition of the barns and the removal of the portacabins

on the site. Nevertheless it is not possible to rule out occasional bat use of such

structures. Therefore the following precautionary approach is recommended:

• All roofing materials should be removed carefully by hand and inspected

for the presence of roosting bats

• All site workers will be made aware of the slight possibility of finding bats

and the procedure to follow should they be found. In the unlikely event

that a bat is discovered, contractors will stop work immediately and

telephone an ecological professional qualified to deal with bats.

Telephone numbers of such will be held on site (Swift Ecology numbers:

07825 711862 or 01926 642541). Further surveys and a European

Protected Species Licence may be required before works can continue.

• Should any bats fall out of structures or be injured, they will be gently

placed in a secure ventilated box (e.g. a cardboard box) by the contractor

and left in a cool dark place, until appropriate advice can be sought. Bats

should not be handled without gloves.

• A copy of these recommendations will be available to site workers and

displayed on site.

6.1.2 Nesting Birds

The roadside hedge and the buildings may be used by nesting birds. All nesting birds

are protected by law. To avoid committing an offence, any works should be

undertaken outside the bird breeding season (March to August inclusive). If this is

not possible, the hedge and buildings should be checked immediately prior to works

commencing by a suitably qualified ecologist. If there are breeding birds present,

works cannot continue until the chicks have fledged and left the nest.

6.2 Habitat Compensation and Biodiversity Enhancement Measures

In order to compensate for the loss of a section of roadside hedge, and to enhance a

site that currently is of relatively low biodiversity value, the following new areas of

wildlife habitat will be created as part of the development (identified on the

architect’s plan in Appendix 1); these will be in addition to new ornamental plantings

close to the buildings that are not considered here:



Native species hedge

A new hedgerow will be established to link the north-west corner of the existing

main building with the roadside to the west. Running roughly east to west and

extending to a length of approximately 15 m, this hedge will comprise locally native

shrub species, including the following:

Field maple Acer campestre Hawthorn Crataegus monogyna Hazel Corylus avellana Dogwood Cornus sanguinea Blackthorn Prunus spinosa Guelder rose Viburnum opulus

Holly Ilex aquifolium

Yew Taxus bacatta

This hedge will be encouraged to grow to a minimum height of 3 m and a minimum

width at its base of 1.5 m. It will be managed so as to retain a dense structure with

active fruiting. It will not be trimmed on both sides every year, so that some fruit

production will be available for consumption by wildlife during the autumn and

winter months.

Strategic block of native trees and shrubs

To the north of the existing main building, linking with the northern end of the

roadside hedge at the north-western corner of the site and extending along the

northern site boundary toward the east, a new, permanent block of native trees and

shrubs will be established. This will comprise a mix of species including standard

trees such as pedunculate oak Quercus robur, wild cherry Prunus avium and silver

birch Betula pendula, as well as the shrubs listed above in connection with the new

hedge. This new block of semi-natural habitat will be managed so as to establish and

maintain a diversity of tree and shrub species, with a two-tier structure comprising a

low density of standard trees over a denser shrub layer with linear gaps.

The planting will be designed strategically to create effective links with existing

hedges and areas of trees and shrubs; this will enhance landscape connectivity for

bats and other wildlife in line with the principles enshrined in Landscape and urban

design for bats and biodiversity (Gunnell et al., 2012). In order to provide a viable

commuting route and foraging area for bats, artificial lighting on the site must be

effectively controlled so that this new habitat feature remains dark at night.



7 RELEVANT LITERATURE

Gunnell, K., Grant, G. and Williams, C. (2012). Landscape and urban design for bats

and biodiversity. Bat Conservation Trust, London.

Hundt, L. (2012). Bat Surveys – Good Practice Guidelines, 2nd edition. Bat

Conservation Trust, London.

Mitchell-Jones, A.J. (2004). Bat Mitigation Guidelines. English Nature, Peterborough,

England.

Schofield, H.W. & Mitchell-Jones, A.J. (2004). The bats of Britain and Ireland. The

Vincent Wildlife Trust, Ledbury, England.

APPENDIX 1 Habitat compensation and enhancement measures

Documents

HEDGE ASSESSMENT AND BAT ACTIVITY SURVEY · 4.2 Bat Activity Survey One bat activity survey was conducted at the site, as described in section 3.2. The raw data from this survey are