Report on monitoring of the wind farm impact on birds in

the vicinity of Gnieżdżewo (gmina Puck, pomorskie

voivodeship)

Piotr Zieliński, Gerard Bela, Andrzej Marchlewski

December, 2008

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Table of contents

1. Introduction…………………………………………………………………………... 4

2. Methods……………………………………………………………………………… 4

2. 1. Countings from an observation point……………………………………………... 4

2. 2. Searching of dead birds…………………………………………………………… 5

3. Results………………………………………………………………………………... 5

3. 1. Avoiding behaviour……………………………………………………………….. 7

3. 2. Flight altitude……………………………………………………………………… 8

3. 3. Impact of weather conditions……………………………………………………… 9

3. 4. Penetration the farm area by predators……………………………………………. 10

3. 5. Mortality of birds caused by collisions with turbines……………………………... 10

4. Protected areas……………………………………………………...……………….. 11

5. Collision risk………………………………………………...………………………. 12

6. Conclusions…………………………………………………………………………... 14

7. References……………………………………………………………………………. 15

8. Maps………………………………………………………………………………….. 16

9. Pictures………………………………………………………………………………. 18

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1. Introduction

The report aims to describe the avifauna of autumn migration within the area of wind farm in

the vicinity of Gnieżdżewo, gm. Puck, pomorskie voivodeship. It has been prepared upon the

order of ”DIPOL spółka z ograniczoną opowiedzialnością” company seated in Warsaw,

Wiertnicza str. 169. The report aims to characterize:

- main parameters of migration on this area;

- collision risk of birds

2. Methods

The purpose of field surveys was to describe a quantitative profile of using the wind farm by

birds during autumn migration. The main parameters estimated during research included:

- the number of particular birds species;

- the composition of bird species.

The range of field studies included:

- counting of birds from an observation point;

○ using airspace by birds;

○ using the area by birds for resting and foraging;

- searching of dead birds under turbines.

2.1. Countings from an observation point

Field studies were carried out in 2008 between September 18th and November 16

th. Birds

were counted during a few-hour on-site observations conducted in different weather

conditions. 7 days were spent on-site in September, 14 days in October and 6 in November.

In total, 27 days were spent in a field, and on average on-site visits were carried out every 2

days. In the peak of migration fallen in October field visits were carried out every 2 days.

They started in early morning hours and lasted up to 8 hours.

To check which bird species may be more collision-prone with turbines, flight altitude of all

birds has been classified into one of 3 categories: 0-40 m, 40-120 m and more then 120 m.

Flight direction has been also noted for all migrating birds. Weather conditions – having

significant impact on flight direction and altitude – has been obtained from Internet

(http://new.meteo.pl/). The following meteorological data have been used: direction and

velocity of wind, cloud cover, temperature and precipitation.

Data from Internet have been enriched in own data noted during field observations. Due to

field topography – the necking of the Płutnica river valley – neighbourhood of a forest and

expected flight direction – observations have been carried out mostly from one point. Bird

behaviour in relation to turbines (avoiding behaviour) was described. Among other things

have been also noted: changes of flight direction resulted from a presence of turbines from 0°

(no change) to 180°(max. change of flight direction) and flight altitude changes.

Data on using farm area by birds for resting and feeding have been collected within

observations from a point, in particular on moving between different turbines. Data

concerning the place of feeding have been also gathered and in the case of raptors – using

updrafts to increase altitude – also the kind of flight. All more numerous bird flocks staying

on a ground were mapped in a scale of 1: 50 000 to show using the area as foraging place.

The number of birds migrating in bigger flocks have been estimated by enlarging the unit of

measure. According to this method, first 10 birds were counted preciously and then the count

was done by tens up to 50. The rest of flock was counted by 50s. Similar method has been

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used to estimate the number of birds feeding and resting on fields. Surveys did not include

birds species migrating at night.

2.2. Searching of dead birds

Searching of birds died due to collisions with turbines, were carried out during every field

visit - on average every 2 days. The area in a radial of 50-70 m around every tower of a

turbine has been searched. In a case when dead bird has been found, finding date, bird

species, age and sex, distance from the base of a turbine have been noted, the kind of injuries

and an approximate time of a collision. All dead birds found under turbines have been

collected. The photographic documentation has been also taken. To estimate how long dead

birds lay under turbines and how quickly are removed by predators, on October 13th 2008 four

dead birds were left, coming from the collection of Ornithological Station Museum and

Institute of Zoology PAS in Gdańsk. There were small species: the Great Tit Parus major, the

Robin Erithacus rubecula, the Yellowhammer Emberiza citrinella and the Song Thrush

Turdus philomelos. Birds have been left under turbines no. 6 and 7. in habitats representative

for the whole of farm area. During each field visit, it was checked from a distance if birds still

lied there. One did not approached them not to leave a smell trace which could lead predatory

mammals to dead birds.

In field studies took part: Andrzej Marchlewski, Gerard Bela, Piotr Zieliński.

3. Results

In autumn, during field surveys on the study area, 9775 birds have been recorded belonging to

51 species. There are – among them – species identified only to a genus: gulls Larus sp. – 911

individuals, swans Cygnus sp. – 9 ind. and passerine birds Passeriformes – 388 individuals.

The identification of these birds was impossible due to conditions – a distance from an

observer and the short time of observation. Recorded numbers of birds concern birds in flight

in given direction (migrating), and also birds that stopped foraging and resting on the

migration route. The most common was the Starling Sturnus vulgaris (n=2711 of individuals;

27% of all recorded birds) observed mainly in flight (n=2001 ind., 73% of all Starlings).

More then 84% of Starlings migrated on altitude up to 40m moving between feeding places

within the study area. Another 15% migrated on altitude between 40 and 120m. For feeding,

the farm area was used by 26% of Starlings. Less numerous were: Bean Geese Anser fabalis

and White-fronted Geese Anser albifrons. One recorded: 986 of migrating geese (n=1008 of

individuals; 97% of all recorded geese). Main migration took place on altitude > 120m (665

of individuals; 67% of all geese). Geese migrated also in large numbers on lesser altitude –

40-120m (n=321 ind.; 32% of all geese). Gulls Larus sp. were observed mainly while

foraging and resting (n=615 ind.; 67% of all gulls), less frequently in flight (n=311 ind.; 34%

of gulls). Moving of gulls took place on altitude up to 40 m, and their occurrence was related

to farmed works within the farm area – gulls foraged on fresh-plugged fields, and also to

weather conditions – during sea storm they rest in large numbers on surrounding fields. Barn

Swallows Hirundo rustica - occurred in large numbers - formed flocks feeding in flight

(n=573 ind., 76% of all observed) , and less frequently were observed during direct migration.

Raptors were represented by 8 species, from which the most numerous were Buzzards Buteo

buteo (n=53 ind., 52% of all recorded raptors). Almost 3 times less numerous was the Kestrel

Falco tinnunculus – the second raptor in accordance to the number. The majority of raptors

were recorded up to 50 m above a ground level while hunting.

Using the farm area for feeding and resting was far lesser then for migration (n=2905 of

individuals; 30% of all birds; 29 of species). The most numerous were small Passerines

(n=2197 ind.; 75% of all feeding), and the most common of them was the Starling (n=710

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ind.; 24% of all feeding birds). Gulls were a bit less common (n=615 ind.; 21% of feeding

birds), and raptors were far less numerous, represented only by 4 species (n=33 ind.; 1% of

feeding birds). As usual, raptors the most frequently were observed on the edge of Płutnica

river valley. Other species used the whole of area evenly for feeding, though some of them,

e.g. Starlings clearly preferred plugged field fragments where they formed large flocks. Very

interesting was the observation of small flock of geese feeding on a corn crop. Such behaviour

resulted from food accessibility. The breakdown of all bird species recorded during field

surveys with their number is in the Table 1.

Table 1. Birds recorded during autumn migration in the wind farm area near Gnieżdżewo in

2008.

Autumn

Bird species migration Total

Flying Foraging

Sturnus vulgaris Starling 2001 710 2711

Anser fabalis + A. albifrons Bean + White-fronted Goose 986 22 1008

Larus sp. Gulls 296 615 911

Hirundo rustica Barn Swallow 175 573 748

Alauda arvensis Skaylark 601 143 744

Miliaria calandra Corn Bunting 393 120 513

Emberiza citrinella Yellowhammer 328 179 507

Passeriformes sp. Passerines 313 75 388

Anthus pratensis Meadow Pipit 326 37 363

Fringilla coelebs Chaffinch 326 326

Vanellus vanellus Lapwing 253 253

Columba palumbus Woodpigeon 239 5 244

Carduelis carduelis Goldfinch 58 163 221

Carduelis cannabina Linnet 79 120 199

Grus grus Crane 74 74

Corvus frugilegus + Corvus monedula Rook + Jackdaw 39 35 74

Passer domesticus House Sparrow 65 65

Phalacrocorax carbo Cormorant 56 56

Buteo buteo Buzzard 35 18 53

Corvus coraz Raven 41 5 46

Columba oenas Stock Dove 19 25 44

Motacilla alba Pied Wagtail 7 19 26

Carduelis spinus Siskin 25 25

Falco tinnunculus Kestrel 11 8 19

Larus argentatus/cachinnans Herring/Yellow-legged Gull 15 15

Carduelis chloris Greenfinch 15 15

Buteo lagopus Rough-legged Buzzard 8 4 12

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Autumn

Bird species migration Total

Flying Foraging

Ardea cinerea Grey Heron 9 2 11

Perdix perdix Grey Partridge 6 5 11

Pluvialis apricaria Golden Plover 11 11

Haliaeetus albicilla White-tailed Eagle 10 10

Coccothraustes coccothraustes Hawfinch 10 10

Cygnus sp. Swans 9 9

Fringilla montifringilla Brambling 8 8

Gallinago gallinago Snipe 4 3 7

Passer montanus Tree Sparrow 7 7

Anas platyrhynchos Mallard 5 5

Emberiza schoeniclus Reed Bunting 5 5

Accipiter nisus Sparrowhawk 2 1 3

Riparia riparia Sand Martin 3 3

Motacilla flava Yellow Wagtail 2 1 3

Milvus milvus Red Kite 2 2

Streptopelia turtur Turtle Dove 2 2

Accipiter gentilis Goshawk 1 1

Falco subbuteo Hobby 1 1

Anthus cervinus Red-throated Pipit 1 1

Anthus trivialis Tree Pipit 1 1

Phoenicurus ochruros Black Redstart 1 1

Acrocephalus schoenobaenus Sadge Warbler 1 1

Lanius excubitor Great Grey Shrike 1 1

Plectrophenax nivalis Snow Bunting 1 1

Total 6870 2905 9775

3.1. Avoiding behaviour

They are all kinds of flight direction changes resulted from the presence of a wind farm (or

other constructions) on the birds migration route. In autumn, during field surveys avoidance

behaviour of 177 birds flying through or over the farm area was recorded (2.5% of all birds

observed in flight) belonging to 10 species (Table 2). Birds avoided turbines by change of

flight direction or change of altitude and direction at once. Changes of flock formation due to

a presence of turbines have been also recorded. Sometimes changes of flight direction took

place between turbines, but most frequently before flying into the farm area and took place on

different altitude. The most frequently flight direction was changed at a rotor-level - 40-120 m

(n=70 of individuals; 40% of all records). Below this altitude (0-40 m) birds changed

direction as frequently as on altitude 40-120 m (n= 54 ind.; 30% of all). Changes of flight

direction were also recorded in birds migrating far from the range of working rotors - > 120 m

(n=53 ind.; 30% of all).

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Change of altitude with flight direction at once were observed in a White-tailed Eagle and 2

flocks of geese. All birds flew at a rotor-level and while approaching to an obstruction they

suddenly increased altitude. Formation changes have been observed in a Cormorants’ flock

which migrated on altitude 40-120 m. All kinds of avoidance behaviour observed on the farm

area are common. In available literature, a described behaviour occurs more often then in a

case of farm near Gnieżdżewo. Usually they concern a few tens of percents of birds e.g. 15-

71%, 75% (Lekuona and Usula 2007, Marczewski 2008). The significant percentage of birds

avoiding the farm is a positive reaction and shows gradual getting accustomed to turbines

what reduces the collision risk.

Table. 2. Avoidance behaviour of particular birds species observed in autumn 2008 according

to the degree of flight direction change.

Changes of flight direction Species

Number

of birds

degrees (o)

20 – 30 White-tailed Eagle, Cormorant, Geese 41

45 Crane, Geese, Grey Heron, Pigeons and Doves 86

90 Skaylark, Crows 50

Total 177

3.2. Flight altitude

More them half of birds flew over the farm area on altitude lesser then 40 m (n=4518 ind.;

65% of all migrating birds) (Fig. 1). On this altitude took place main migration of passerine

birds. Below this altitude have been also recorded raptors, mostly Buzzards that hunted in

hovering flight. Main migration of geese took place on considerable altitude and concerned

birds in transit flight.

However, very interesting were the observations of geese flying on the significantly lower

altitude – at a rotor-level (40-120 m) (n=321 ind.; 32 % migrating geese). Presumably, the

decrease of migration height was caused by stronger wind from western direction reached up

to 30km/h.

Moreover, geese – and other large size, little maneuverable birds migrating low over Puck bay

were unable to correct flight direction or altitude over the farm area. They fly low and

increase the collision risk. Presumably the low flight of geese was caused by a presence of

corn crop which was an attractive feeding place.

In autumn 2008, 74 flying Cranes (100% of all recorded) have been recorded. The

majority of them migrated on altitude 40-120 m (n=54 ind.; 70% of all recorded) and only

10% of birds (n=7 ind.) migrated on lower altitude. Over 120 m were observed small groups

of 3-4 migrating birds (n=15 ind.; 20% of all recorded). Significant decrease of flight altitude

of flying Cranes observed in autumn, presumably was related to a corn crop occurred in a

part of farmed fields.

Nearby the turbine no. 6 occurred a farm field which after harvesting was an attractive

feeding place for different bird species - cranes among them - that in this season feed on corn

crops. Decrease of flight altitude and birds behaviour confirm the attractiveness of this place.

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Fig. 1. Migration altitude of Passerines, Cranes, raptors, wildfowl and all birds in a total, in

autumn 2008.

3.3. Impact of weather conditions

The most intensive migration took place at middle wind velocity reached 11-20 km/h. In such

conditions migrated 48% of birds (n=3325 of individuals). Lesser intensity of migration was

observed at weak wind 0-10 km/h (n=2367 ind.; 34% of all migrated birds). Migration taking

place against strong wind made some species (e.g. geese) reduce altitude. The flying intensity

depended upon not only wind velocity, but also direction, so birds most frequently migrated

against western to south-western wind, but also against southern one.

In autumn, main direction of migration - on this area – was toward west (n=2769 ind.; 64% of

migrants). A bit less of birds migrated toward south (n=676 ind.; 15% of migrants) (Fig. 2).

Such differences were caused by variable wind direction.

Unfavorably weather conditions, such as: rain, fog or strong wind make birds reduce flight

altitude (Winden et al. 1999). According to some authors, the most frequently altitude is

decreased during strong front wind with the highest altitude during a rear wind and high

Passerines

0 1000 2000 3000 4000 5000

0-40

40-120

> 120

Number of birds

[m]

Cranes

0 20 40 60

0-40

40-120

> 120

Number of birds

[m]

Raptors

0 20 40 60

0-40

40-120

> 120

Number of birds

[m]

Wildfowl

0 200 400 600 800

0-40

40-120

> 120

Number of birds

[m]

All species

0% 50% 100%

0-40

40-120

> 120

[m]

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pressure. In such conditions birds need less of energy, especially large size species and birds

relatively little maneuverable (Klaassen et al. 2004, Liechti 2006).

N

NE

E

SE

S

SW

W

NW

3.4. Penetration the farm area by predators

According to carried experiment with dead birds left under turbines one may conclude that a

penetration of the farm area by predators was significant. Left Great Tit and a Yellowhammer

disappeared after 1 day, a Song Thrush after 3 days and a Robin after 8 days. An average time

of exposition was almost 3.5 days. Thus, one may assume that while looking for dead birds

carried out on average every 2 days, the majority of victims has been found.

3.5. Mortality of birds caused by collisions with turbines

In autumn 2008, 5 birds died due to collisions with turbines were found – 4 Goldcrests

Regulus regulus (Photo1) and 1 hybrid between Peregrine Falco peregrinus and Gyrfalcon

Falco rusticolus (Photo 2, 3), (Table 3), (Fig. 3). Goldcrests were found under different

turbines, however, the majority of them in western part of the wind farm. Birds were found at

a small distance to towers – on average 15.5 m. All found individuals were young females. In

Poland, the Goldcrest is a numerous species, occurring in breeding season and during

migration. In some years it is the invasive species (Tomiałojć, Stawarczyk 2003).

The hybrid falcon found under the turbine no. 4 came from a falcon husbandry. It escaped

from captivity in Germany nearby Frankfurt more then 3 months earlier. The bird covered

about 800 km directing to Polish sea coast where first time was seen on September 13th 2008

in the Reda river mouth near Reda town. In a wild, the Peregrine and the Gyrfalcon do not

hybridize, although their breeding ranges are similar (Randler 2002). However, in falcon

husbandries the intentional hybridization is a method to enlarge versatility of birds used for

hunting. Keeping birds in captivity causes the disappearance of some kinds of behaviour

normally observed in a wild in falcons and other raptors.

Birds escaped from husbandries are less skittish and decrease an escape distance, associate

people with “food” and do not avoid the contact with them.

All these kinds of behaviour increase the collisions risk caused by antrophogenic factors.

All birds found under turbines were relatively fresh what indicates the collision at night or

early morning hours. Evidently, collisions of some birds were caused by weather conditions –

fog limiting visibility. After foggy day two Goldcrests were found.

Death of birds may take place at the moment of collision or later as a result of internal or

external injuries (Drewitt, Langston 2006). Goldcrests found under turbines died probably due

to internal injuries. However, the falcon had partially cut wing in ulna. Although, mortality of

birds caused by collisions increased in 2008, significant is a species composition of died

birds. In the wind farm near Gnieżdżewo collisions concerned common and widespread

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species that are not vulnerable. However, the negative impact on population, especially

breeding, is more significant for species: rare and vulnerable, long-lived and with slow

maturation rates and low productivity of young (Marczewski 2008). For such species even

little increase of mortality has significant impact on population.

Mortality of birds due to collisions with turbines near Gnieżdżewo was 0.4 birds per a turbine

in the period 18.09.2008-16.11.2008 and stayed on a low level.

Died Goldcrests found within farm area near Gnieżdżewo are:

• protected under art. 33 par. 1. of Act on Nature Protection;

• are not listed in Annex 1 of Birds Directive (EU Directive 79/409/EWG on the protection of

wild birds);

• are not listed in Polish Red Book of Animals (Głowaciński 2001).

Table 3. Dead birds found under turbines near Gnieżdżewo in autumn 2008. No. of birds –

number of died birds; Dist. – distance from tower; Exp. – exposition – direction.

Species

No.of

birds Sex/age

No.

of Dist. Exp. Date

os. turbine (m)

Regulus regulus Goldcrest 1 young female 4 19 SW 24.09.2008

Falco peregrinus x F. rusticolus Peregrine x Gyrfalcon 1 young 4 11 SE 30.09.2008

Regulus regulus Goldcrest 1 young female 2 12 W 07.10.2008

Regulus regulus Goldcrest 1 young female 3 28 E 11.10.2008

Regulus regulus Goldcrest 1 young female 8 4 N 04.11.2008

4. Protected areas

There are 3 protected areas in neighbourhood of the wind farm – listed by BirdLife

International as Important Bird Areas (IBA) of European Importance (Sidło et al. 2004). All

these areas are protected under Nature 2000 as so-called Special Protected Areas (SPA).

- Puck Bay (code of Nature 2000 site: PLB 220005). Borders of this area are some

1300m from the farm toward east. There are at least 28 breeding bird species listed in

Annex 1 to the Birds Directive. The Puck Bay is one of the most important places for

wintering and stopping of waterbirds during spring and autumn migration on the

Southern Baltic. The site has been classified for the protection according to numbers

of Cormorants Phalacrocorax carbo, Tufted Ducks Aythya fuligula and Long-tailed

Ducks Clangula hyemalis (Meissner, Sikora 2004).

- Darzlubska Forest (code of Nature 2000 site: PLB220007). The site is located about

4500m from the farm toward south-west. On this area, have been recorded at least 13

species listed in Annex 1 to the Birds Directive. The site is one of 10 the most

important breeding area of Tengmalm’s Owls Aegolius funereus. According to this

species the site has been classified for protection (Błaszczyk, Sikora 2004).

- Bielawa Swamps (code of Nature 2000 area: PLB220003). The area is located about

8500m from the farm toward north-west. On the area, at least 32 species of birds

listed in Annex 1 to the Birds Directive have been recorded. The qualifying species for

the protection of Bielawa Swamps was the Crane Grus grus which use this site for

night roosting while spring and autumn migration (Sikora, Półtorak 2004).

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Neighbourhood of the wind farm with Nature 2000 protection areas indicates the necessity to

estimate the impact of the investment on the object of protection in the site, that are qualifying

species and it should be “habitat assessment” (see art. 6 of Habitat Directive UE). It should be

done within a confines of pre-investment monitoring. Thus, especially important is the

assessment of the negative impact of an investment on species from Puck Bay and Bielawa

Swamp.

Lesser negative impact (or its lack) has the investment on birds protected in Darzlubska

Forest due to habitat preferences – forest birds. It should be indicated for the possibility of

moving White-tailed Eagles and other raptors between breeding areas in Darzlubska Forest

and foraging out of forest and on the Puck Bay.

- Puck Bay. The potential impact of the farm may concern wildfowl, i.e. swans, geese,

Cormorants, ducks forming numerous flocks on water. Some of them (swans, ducks) at

night or day fly on the surrounding farm fields to forage. Because they are large birds,

little maneuverable, they fly over the farm area on altitude 40-120 m what increase the

collision risk. In the years 2007-2008 through the farm area migrated more then 8

thousands of birds mentioned above. The Cormorant constituted 4% (n=327 individuals),

swans (3 species) 4% (n=340 individuals), geese 78% (n=6290 species). Surveys carried

out on the Puck Bay by Waterbirds Reasearch Group KULING indicated that numbers of

Cormorants and swans from two years varied between 9-19 thousands. In the same period

swans were less numerous, 1900 individuals and 1100 individuals

(http: www.kuling.org.pl/liczenia/archiwa/lz2007.htm). In relation to the stage of annual

cycle through the farm area migrate between 1% and 3% of Cormorants and 17% - 28%

of swans. Following data indicate that little percentage of Cormorants protected in this site

may be potentially collision-prone. A bit more collision-prone seem to be swans, though

the lack of collisions confirms effective avoiding the turbines by these birds. As a result,

the farm area have not the negative impact on qualifying species (or other too) occurring

on the site of Nature 2000 – the Puck Bay.

- Bielawa Swamps. The potential impact of the farm may concern Cranes.

Observations carried out while monitoring indicated univocally that Cranes relatively

seldom were recorded on the study area. They constituted 3% of all recorded birds in

the years 2006-2008 (n=2552 of Cranes; n=75 509 of all recorded birds). More then

75% of birds were observed during flight on considerable altitude (> 120 m).

Between 40-120 m migrated 21% of Cranes. The occurrence of Cranes on the wind

farm area or its nearest vicinity was related to kinds of farmed fields. When the

suitable food base exists – fields after corn harvesting, the number of observed Cranes

significantly increases. This thesis confirmed data from 2006 when within study area

on corn crops foraged 760 Cranes. The birds arrived to feeding place directly from a

night roosting place located in Bielawa Swamps. The negative impact of the wind

farm on Cranes may occur in the situation when exists a suitable food base within the

area of wind farm or its neighbourhood.

5. Collision risk

During post-investment period (the years 2007-2008) 10 birds died due to collisions

with turbines were found, 3 individuals in year 2007 and 7 in 2008. Dead birds were

found under 7 turbines (n=63%). Under 3 turbines more then 1 bird were found in a

given season, and the most collide were turbines no. 3, 4, 7 (Fig. 4). Of 4 species,

Goldcrests were the most frequently found (n=7 individuals; 70% of dead birds), and

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other species were found individually. Birds collided with turbines as frequently in

spring (n=5 individuals) as in autumn (n=5 individuals).

In spring 2007, 5 bats were also found, mainly Nathusius’ Pipistrelle

Pipistrellus nathusii. Single individuals were under turbines no. 1 and 8, and 3 under

turbine no. 6. In total, when including birds and bats, in the years 2007-2008 collisions

related to 81% of turbines.

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6. Conclusions

1. During autumn field surveys 9775 birds were recorded belonging to 51 species. The

vast majority of birds was observed in flight (70%) during active migration and while

feeding. Less numerous birds were observed on a ground – using the area for resting

and feeding (30%). As in previous years, also in this autumn the most common were

small passerine birds – Starlings Sturnus vulgaris.

2. Avoiding behaviours of migrating birds were observed in 177 individuals belonging to

10 species. They were observed in 2.5% of all birds recorded in flight, both small

(Skylarks) and large-size species (e.g. Cranes, White-tailed Eagle). Birds responded to

an obstruction by flight direction change, change of altitude and flock formation.

Observed kinds of behaviour did not differ in frequency in ranges of altitude: 0-40m,

40-120m, > 120m.

3. Migration took place mainly between 0-40m and concerned 65% of flying birds. On

this altitude took place mostly migration of Passerines. Decrease of altitude by

migrating geese and Cranes has been observed. Presumably it was a result of weather

conditions and the presence of attractive feeding place, what was confirmed by birds

behaviour - trying to land on a corn crop within the farm area.

- The occurrence of corn crops within the wind farm or in neighbourhood

may increase the attractiveness of this area for big-size species, e.g. Cranes, geese,

swans. The attractive foraging place will increase the number of birds within the

farm area and the vicinity, and as a result the collision risk will also increase

significantly.

4. The majority of birds migrated during middle wind blowing from western direction.

64% of birds migrated toward west.

5. The penetration of the farm area by predators was significant. Regularly, foxes and

domestic cats were observed moving within the farm. An average time of exposition

of left birds (a Great Tit Parus major, a Yellowhammer Emberiza citrinella, a Song

Thrush Turdus philomelos, a Robin Erithacus rubecula) was almost three and half of

days.

6. In autumn 2008, 5 birds died due to collisions with turbines were found. Four of them

- Goldcrests Regulus regulus - were found under turbines no. 2, 3, 4, 8. Under the

turbine no. 4 also was found a hybrid falcon – the Peregrine Falco peregrinus and the

Gyrfalcon Falco rusticolus escaped in summer 2008 from a falcon husbandry.

In the years 2007-2008 10 dead birds from 4 species were found . The most collision-

prone species is the Goldcrest (n=7 of individuals; 70% of dead birds). Collisions took

places with 7 turbines (63% of turbines). When including also bats - 81% of turbines.

7. In autumn, mortality of birds due to collisions with turbines near Gnieżdżewo is still

on a low level and did not exceeded 0.4 birds per turbine during 2 month surveys

(18.09-16.11.2008)

- Difficulties to interpret the collision risk and its comparison with data from

literature result from: firstly, short period of field surveys and secondly, data

coming from 11 selected turbines. It would be advisable to estimate the collision

risk of all turbines within the area.

8. In spite of little distance between the farm area and 3 Nature 2000 protected areas: the

Puck Bay, Darzlubska Forest and Bielawa Swamps, the negative impact of the wind

farm on birds (so-called qualifying species) seems to be small. It results from small

numbers of protected species on these sites (e.g. Cormorants, swans, geese) and short-

term using the airspace by them.

15

7. References

Błaszczyk K., Sikora A. 2004. Puszcza Darżlubska. Ss. 142-145 w: Sidło P.O., Błaszkowska

B. & Chylarecki P. (red) Ostoje ptaków o randze europejskiej w Polsce. OTOP: Warszawa

Drewitt A. L., Langston R. H. W. 2006. Assessing the impacts of wind farms on birds. Ibis

148: 29-42.

Głowaciński Z. (red.) 2001. Polska czerwona księga zwierząt - kręgowce. PWRiL, Warszawa.

Klaassen M., Beekman J. H., Kontiokorpi J., Mulder R. J. W., Nolet B. A. 2004. Migrating

swans profit from favourable changes in wind conditions at low altitude. J Ornithol 145: 142-

151

Liechti F. 2006. Birds: blowin’ by the wind? J Ornithol 147: 202-211.

Leukona J. M., Ursula C. 2007. Avian mortality in wind Power plants of Navarra (Northern

Spain). In: de Lucas M., Janss G. F. E., Ferrer M. (eds) Birds and wind farms. Risk

Assessment and mitigation. Quercus, Madrid.

Marczewski A. 2008. Wpływ elektrowni wiatrowych na ptaki w Europie i Ameryce

Północnej. Praca licencjacka. Szkoła Główna Gospodarstwa Wiejskiego. Warszawa.

Meissner W., Sikora A. 2004. Zatoka Pucka. Ss. 146-149 w: Sidło P.O., Błaszkowska B. &

Chylarecki P. (red) Ostoje ptaków o randze europejskiej w Polsce. OTOP: Warszawa

Randler Ch. 2002. Avian hybridization, mixed pairing and female choice. Animal Behaviour

63, 103-119

Sikora A, Półtorak W. 2004. Bielawskie Błota. Ss. 137-141 in: Sidło P.O., Błaszkowska B. &

Chylarecki P. (red) Ostoje ptaków o randze europejskiej w Polsce. OTOP: Warszawa

Tomiałojć L. & Stawarczyk T. 2003. Awifauna Polski: rozmieszczenie, liczebność i

zmiany. PTPP "pro Natura", Wrocław.

van dre Winden J., Spaans A. L. & Dirksen S. 1999. Noctural collision risks of local

wintering birds with wind turbines in wetlands. Bremer Beitrage fur Naturkunde und

Naturschutz 4: 33-38.

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8. Maps

8

2

5

6

4

11

9 10

3

7

1

Dead birds ptaki Wind turbines

Study area badań

Fig. 3. Location of birds died due to collisions with turbines near Gnieżdżewo in autumn

2008. Digits – numbers of wind turbines assumed for the purposes of this report.

17

8

2

5

6

4

11

9 10

3

7

1

Wind turbines

Dead birds 2008

Dead birds 2007

Study area badań

Fig. 4. Location of birds died due to collision with wind turbines near Gnieżdżewo in the

years 2007/2008. Digits – numbers of wind turbines assumed for the purposes of this report.

18

9. Photos

Photo 1. Dead Goldcrest Regulus regulus found under the turbine no. 8 in the farm area near

Gnieżdżewo in autumn 2008. (A. Marchlewski).

Photo 2. Dead hybrid falcon between the Peregrine Falco peregrinus and the Gyrfalcon Falco

rusticolus found under the turbine no. 4 in the farm area near Gnieżdżewo in autumn 2008. (A.

Kośmicki).

19

Photo 3. Dead hybrid falcon between the Peregrine Falco peregrinus and the Gyrfalcon Falco

rusticolus found under the turbine no. 4 in the farm area near Gnieżdżewo in autumn 2008. On legs are

visible husbandry rings and a radio-trasmitter (A. Kośmicki).