Report on monitoring of the wind farm impact on birds in the vicinity of Gnieżdżewo (gmina Puck, woj. pomorskie)

Transcription

1 Report on monitoring of the wind farm impact on birds in the vicinity of Gnieżdżewo (gmina Puck, woj. pomorskie) Piotr Zieliński, Gerard Bela, Andrzej Marchlewski Gdańsk, December 2010

2 Piotr Zieliński Ornithological Station Museum and Institute of Zoology Polish Academy of Sciences Nadwiślańska 108, Gdańsk tel Gerard Bela Os. Słoneczne 13/ Garzyn tel Andrzej Marchlewski Wejherowska Puck 2

3 Table of contents 1. Introduction Methods Counting from the observation point Searching of dead birds Results Brief characteristic of migration Conservation status of birds Avoidance behaviour Flight altitude Mortality of birds caused by collisions with turbines The Black-headed Gull Larus ridibundus The Skylark Alauda arvensis The Goldcrest Regulus regulus Collisions of bats Intensity of airspace use Collisions in the years Conclusions Literatura

4 1. Introduction The report describing autumn migration of birds in the vicinity of Gnieżdżewo, gm. Puck, pomorskie voivodeship has been prepared upon the order of DIPOL Spółka z ograniczoną odpowiedzialnością seated in Warsaw, Wiertnicza 169 and Farma Wiatrowa Łebcz sp. z o.o. seated in Warsaw, Królowej Marysieńki 10. Monitoring conducted in autumn 2010 was the continuation of surveys started in spring Data collected during the next season enabled better estimation of using this area by birds, the collision risk and deterring effect. The report contains also data on the collision risk of bats collected during basic surveys of avifauna. 2. Methods Methods of data collecting have not been changed in comparison to previous years of surveys. Field studies aimed to describe bird species composition and their numbers within the farm area during autumn migration and mortality resulted from collisions with turbines. The monitoring was conducted under all turbines: Dipol 11 turbines, Łebcz 8 turbines. Field surveys were based on: - counting of birds from observation points; collected data enabled to describe the airspace use by birds; enabled to describe composition of birds that occur in this area; enabled to estimate using the area as foraging and resting place. - searching of dead birds and bats; collected data enabled to estimate mortality of birds and bats died due to collisions with turbines Counting from the observation point As in previous years surveys were conducted from the middle of September to the middle of November ( ). The basic assumption of the monitoring was collecting long-term data in the same way, so birds counting methods have not been changed in comparison to previous years. Field surveys were carried out during a few-hour on-site visits conducted in different weather conditions from 1-2 points. In total, field studies (excluding searching of dead birds) were carried out during 68 hours (the range: 1-6 hours a day) and mean time of counting on the observation point was almost 3 hours (2,8 hours). Counting of birds started in early morning and lasted up to 6 hours. There were, in total, 24 days spent in a field. On average, on-site visits were done every 2,5 days. In September, 5 visits were done, in October 13, and in November 6. Time of field visits depended on weather conditions (shortened when migration was poor, e.g. due to raining or fog). There were also a few on-site visits done by 3 observers. To estimate the airspace use by birds and estimating which species may be mostcollision prone with turbines, flight altitude has been classified into one of 3 categories: 0-40 m, m and more than 120 m. Flight direction was also noticed. Weather conditions having the significant impact on flight direction and altitude - have been obtained from the Internet ( Following meteorological data have been collected: direction and velocity of wind, a cloud cover, temperature and precipitation. Data were enriched in own data gathered in a 4

5 field. In spite of the location the necking of the Płutnica river valley, neighbourhood of a forest and expected flight direction, surveys were carried out mostly from one point. Birds behaviour in response to the presence of turbines on their flyway were recorded (so called avoidance behaviour). Among other things were noticed: changes of flight direction resulted from a presence of turbines from 0 (no change) to 180 (max. change of flight direction), changes of flight altitude and other kinds of behavior (e.g. changes of a flock formation. Data on farm area use by birds for resting and feeding were collected mostly during walking between particular turbines, but also while observation from a point. Data on foraging places were also recorded. All bigger flocks staying on a ground were mapped in a scale of 1: to show the farm area use as a feeding place. The number of birds migrating in numerous flocks were estimated by enlarging the unit of measure. The method was based on precious counting of 10 birds and than the count was done by tens to 50. The rest of the flock was counted by 50. Similar method has been used to estimate the number of birds feeding and resting on fields. Field studies did not include birds migrating at night Searching of dead birds Searching of dead birds died due to collisions with turbines were carried out during each on-site visit on average every 2.5 days. The area in a radial of 70 m around each turbine was inspected. Searching of dead birds lasted 4-6 hours, usually after counting from an observation point. If the field visit on the day did not include all turbines, searching was continued on the next day. There were also a few on-site visits carried out by the group of 3 observers. In case when a dead bird was found, bird species, age, sex, date, a distance to a tower, a kind of injuries and approximate time of the collision were recorded. All dead birds found under turbines have been collected. The photographic documentation has been taken. While searching the area around turbines all bats that crashed with turbines were also collected. Dead individuals were identified by chiropterologists from Gdańsk University. In field studies took part: Andrzej Marchlewski, Gerard Bela, Piotr Zieliński. 3. Results Brief characteristic of migration In 2010, autumn migration was less intensive in comparison to previous years. This autumn, were recorded within the study area two times less birds (N=6332 ind.), while in the years mean numbers were more than 13 thousands of individuals. Birds in this area were recorded during flight in a given direction (long-range flight) or during stop in migration for foraging and resting. There were recorded, in total, 47 bird species. Among them, were also birds identified only to a genus: gulls Laridae and Passerines Passeriformes (Table 1). The identification of these birds were impossible due to difficult conditions of observation, mostly the distance to an observer. To illustrate migration dynamics, the number of birds from particular orders have been shown in 5-day periods (Fig. 1). Migration and the number of birds during the whole of autumn fluctuated. Typical for this period were sudden increases in one 5-day period and unexpected decrease in the next one. Birds were most numerous in October (56-60th 5-day periods). In this time were recorded 70% (N=4436 ind.) of all birds from the whole of autumn. Two peaks of migration were recorded in the 56th 5-day period ( , N=1562 ind.) and in 60th 5-day period ( , N=1606 ind.). On average, in each 5-day period migrated 487 individuals and the highest diversity was noticed in peaks of migration adequately by 7 and 6 5

6 species. Most noticeable and numerous was migration of Passerines, gulls, waders and pigeons. Other orders of birds were recorded seldom and less numerous, though some of them, e.g. raptors were observed during 87% of field visits (Fig. 1). During autumn migration the farm area was used by species protected under the art. 33 par. 1 of Act on Nature Protection, but also listed in the Annex I of EU Birds Directive. In total, 20 valuable and vulnerable bird species in Europe have been recorded (Table 1). Table 1. Birds recorded during autumn migration within the farm area near Gnieżdżewo in P birds in flight, Z feeding birds. Ann. I species listed in the Annex I of EU Birds Directive, SPEC 1 and 2 species of global conservation concern under the criteria of Birdlife International, PRDB birds listed in Polish Red Data Book of Animals. Autumn Species migration Total Ann. I SPEC 1 and 2 PRDB P Z Sturnus vulgaris Starling Pluvialis apricaria Golden Plover yes yes Columba palumbus Wood Pigeon Corvus frugilegus + monedula Rook + Jackdaw Passer sp. Passerines Larus argentatus/cachinnans Herring/Caspian Gull Emberiza citrinella Yellowhammer Carduelis cannabina Linnet yes Larus sp. Gulls Alauda arvensis Skylark Hirundo rustica Barn Swallow Anthus pratensis Meadow Pipit Buteo buteo Buzzard Corvus corax Raven Anser sp. Geese Grus grus Crane yes yes Larus canus Common Gull yes Carduelis flammea Redpoll yes Larus ridibundus Black-headed Gull Emberiza calandra Corn Bunting yes Apus apus Swift Turdus pilaris Fieldfare Anas platyrhynchos Mallard Falco tinnunculus Kestrel Columba oenas Stock Dove Cygnus sp. swans Buteo lagopus Rough-legged Buzzard Lanius excubitor Great Grey Shrike Motacilla alba White Wagtail Pica pica Magpie Accipiter gentilis Goshawk Circus aeruginosus Marsh Harrier yes Gallinago gallinago Snipe Haliaeetus albicilla White-tailed Eagle yes yes yes Philomachus pugnax Roof yes yes 6

7 Autumn Species migration Total Ann. I SPEC 1 and 2 PRDB P Z Corvus corone cornix Hooded Crow Cygnus olor Mute Swan Phalacrocorax carbo Cormorant Milvus milvus Red Kite yes yes yes Accipiter nisus Sparrowhawk Branta leucopsis Barnacle Goose yes Carduelis carduelis Goldfinch Circus cyaneus Hen Harrier yes yes Calidris ferruginea Curlew Sandpiper Dendrocopos major Great Woodpecker Oenanthe oenanthe Wheatear Anthus cervinus Red-throated Pipit Garrulus glandarius Jay Turdus merula Blackbird TOTAL The number of birds day periods Bla Goł Mew Dra Cha Wró Żur Fig. 1. Changes of the number of birds in 5-day periods in autumn 2010 divided into orders. Bla wildfowl, Goł pigeons, Mew gulls, Dra raptors, Cha waders, Wró Passerines, Żur - cranes. 7

8 The most numerous bird species occurred in the farm area was the Starling (N=1590 ind., 25% of all recorded birds). The great majority of these birds (N=1186 ind., 74%) was observed in flight, other individuals used the area for feeding (N=404 ind., 26%). Almost all migrated Starlings were observed low above ground in the range of altitude 0-40 m (N=1181 ind.), few Starlings flew on altitude m. Second species, according to the number, was the Golden Plover (N=717 ind., 11% of all birds) that were noticed only in flight. Birds used for migration all altitude ranges: 0-40 m 46 ind. (6%), m 450 ind. (62%), >120 m 221 ind. (30%). Golden Plovers most often used the working rotor level ( m), but they also flew above turbines. The airspace use by this species was very intensive, but shortterm, they were recorded only during 3 field visits. The number of recorded Wood Pigeons was almost the same N=682 ind., 10% of all recorded birds), such as Rooks and Jackdaws (N=646 ind., 10% of all birds), that were observed in mixed-species flocks. More than 78% (N=535 ind.) of Wood Pigeons were noticed while feeding on fields, however other species migrated in the similar number at altitude m. Flocks of Rooks and Jackdaws were noticed only in flight. The airspace use by birds was almost exclusively restricted to altitude 0-40 m 21% of birds (N=140 ind.) and m 78% of birds (N=504 ind.). These two species were observed only during 5 field visits this autumn. Most noticeable and simultaneously most numerous was migration of small Passerines that were almost 63% of all birds recorded in the autumn. Percentages of other numerous bird species was similar: pigeons 10%, waders and gulls by 11%. Passerines were represented by 21 species, waders by 4 species, gulls by 3 and pigeons by 2 species. During autumn migration the farm area was used by birds for flying in a given direction or feeding. Some of the species were observed only in flight, e.g. cranes and geese. Flying birds were 61% (N=3894 ind.) and individuals stopped feeding 39% (N=2438 ind.). Most numerous among flying birds were Passerines 66% (N=2609 ind.), waders 19% (N- 723 ind.) and gulls 6% (N=223 ind.). Among feeding birds most numerous were also Passerines 56% (N=1379 ind.), gulls 20% (N=485 ind.) and pigeons 22% (N=535 ind.) (Fig. 2). The wind farm area was regularly used for foraging only by Passerines and raptors. Other most numerous bird orders were recorded seldom, but in high numbers, e.g. gulls and pigeons were very rare and their high numbers resulted from food availability. Attractiveness of this area were caused by farm works that birds foraged intensively. 2% 4% 1% 1% 1% Migrating 2% 0% 0% 0% Foraging 6% Wró 22% Wró Cha Cha Mew Mew 19% Goł Goł Bla Bla Dra Dra 66% Żur Inne 20% 0% 56% Żur Inne Fig. 2. The wind farm use by birds for migration and for feeding during autumn migration in Wró Passerines, Cha waders, Mew - gulls, Goł pigeons, Bla wildfowl, Dra raptors, Żur cranes, Inne other species. 8

9 3. 2. Conservation status of birds In total, during field studies, 20 bird species were recorded, listed in Annex I of EU Birds Directive (7 species), Polish Red Data Book of Animals (6 species) and so called species of European conservation concern; SPEC categories 1 and 2 (7 species), under the criteria of BirdLife International (2004) (Table 1). Polish red data book of animals includes basic information on birds (and other vertebrates) that population in different degrees are vulnerable to significant decline of the number and in extreme cases to the extinction in the country. There are on the list such species that the number declined to critic level, that are threatened due to their small population or unexpected decline of the number (Głowaciński 2001). Birds from the SPEC list under the criteria of Birdlife International (2004) this is a group of priority species in order that conservation action can be taken to improve their breeding status in Europe. There are a few SPEC categories with most important: SPEC 1 species of global conservation concern; SPEC 2 birds not threatened globally, but with unfavorable conservation status in Europe and with global population concentrated on the continent Avoidance behaviour In autumn 2010, the number of avoidance behaviour cases resulted from the presence of the wind farm was very small. Undoubtedly, this resulted from very small number of birds migrated throughout the farm. The frequency of avoidance behaviour occurrence caused by turbines present on a route depends on birds species composition and intensity of the airspace use by birds the lesser number of birds observed on the area, the lesser number of avoidance behaviour cases. Similar rules relate to mortality of birds. Among different kinds of behaviour of birds migrated nearby wind turbines, in autumn were recorded only change of flight direction by 90 and omitting the whole of the wind farm. Avoidance behaviour resulted from the presence of the wind farm on birds migration route were recorded at 91 individuals from 6 species 7% of all birds recorded in flight. Omitting the whole of the wind farm were recorded most often by gulls (the Black-headed Gull, Herring/Caspian Gull) 61 individuals (73%) that migrated in all three altitude zones. Such kind of behaviour seldom concerned small Passerines and large-size species (cranes, swans). In the zone up to 40 m over ground, 20% of all cases of avoidance behaviour were noticed. Most seldom such behaviour was recorded in a collision-zone, and most often birds changed the flight direction at altitude above 120 m 76% of all birds showing avoidance behaviour. Dipol turbines caused changes the flight direction of 20 birds from 2 species. However, the majority of birds omitted the whole of the wind farm 71 individuals, 4 species (Table 2.) Table 2. Avoidance behaviour of particular bird species resulted from the presence of wind turbines, recorded in autumn Avoidance behaviour Species Number Turbines of changes of direction other individuals 90 o - Starling 2 Dipol - omitting Linnet 18 Dipol - omitting Herring/Caspian Gull 53 Łebcz + Dipol - omitting Black-headed Gull 8 Łebcz + Dipol 9

10 Avoidance behaviour Species Number Turbines of changes of direction other individuals - omitting Mute Swan 2 Łebcz + Dipol - omitting Crane 8 Łebcz + Dipol Total Flight altitude Seasonal migration is related to straitened circumstances of food on breeding area what obligate birds to fly toward wintering places. The velocity of migration is related to gathered energetic supplies. Additively birds minimize their energetic costs flying while most favorable conditions. There was also found the susceptibility to velocity of wind and relations between the date of beginning of migration, wind velocity and its direction. Altitude depends also on other weather conditions. On days with no cloud cover birds fly much higher than during cloudy weather (Elkins 2004). Also, bird species, their size, kind and velocity of flight is related to altitude. In the vicinity of Gnieżdżewo birds used usually the lowest zone 0-40 m. In this zone took place migration of 56% of birds (N=2185 ind.). Next altitude zone ( m) was used for flight by 33% of birds (N=1285 ind.), higher (> 120 m) migration was less intensive. In this zone 11% of birds were recorded (N=424 ind.) (Fig. 3). The highest diversity of bird species was noticed up to 40 m. At this altitude 32 bird species were recorded, and the main part in this group were Passerines. In two other altitude zones were recorded similar number of species (adequately 15 and 11), however along with increasing altitude, the number of small Passerines decreased, but grew the number of birds middle- and large-size. Such differences in migration in particular altitude zones result from possibility of their detection by an observer. Small birds are detected and recognized mostly by their voice and recorded at lower altitude. Their detection is difficult during bad weather conditions, e.g. when wind blows or during high pressure weather when birds fly at high altitude. In autumn, raptors migrated most often at altitude lesser than 40 m - 63% (N=55 ind.). In the collision zone ( m) 20% of birds were observed (N=17 ind.), and higher (> 120 m) 17% (N=15 ind.) (Fig. 3). Most numerous of all 8 raptor species was the Buzzard 77% (N=67 ind.). Other species were much more rare, though Kestrels were 10% of this group (N=9 ind.), and Rough-legged Buzzards 5% (N=5 ind.) (Fig. 3). Waders used the airspace mostly in two zone of altitude. The majority of them almost 63% (N=450 ind.) were recorded in the collision zone ( m). Higher migrated 30% of waders (N=221 ind.). The least number of birds only 7% (N=52 ind.) used altitude up to 40 m above ground (Fig. 3). In autumn, only 4 wader species were recorded that almost exclusively migrated above the study area. Most numerous in this group were Golden Plovers 99% (N=717 ind.) of all waders. In spite of the high number of this species and using for flight the collision zone Golden Plovers were recorded seldom. The occurrence of this species was restricted to 3 observations. Each of them was different moving of small flocks of birds above 120 m toward different directions 31 % of individuals (N=221 ind.) and short, lasting a few minutes, using the zone m by flock of birds making circles (62%, N=450 ind.) that were frightened away from a ground. Main migration of small Passerines took place low above ground (0-40 m) (Fig. 3). This altitude was used by 75 % of birds (N=1947 ind.). Higher, between m migrated lesser number of birds (25%, N=658 ind.) and in the highest zone only few individuals were recorded. The diversity of species from this group was changing along with increasing 10

11 altitude. At the lowest altitude was recorded the highest number of species till 13, higher only 5, and > 120 m only 2. Fluctuations of species diversity in particular altitude zones was related to detectability of Passerines. Gulls used the farm area for moving at different altitudes between feeding places (Fig. 3). Depending on intensity of farm works (gulls feed on fresh-plugged fields) birds appeared in the area with various intensity. Most often were observed during flight above 120 m (53%, N=120 m) toward north where the rubbish-dump and the fishing port are. Only 17% of birds (N=38 ind.) were noticed at altitude m. However, 30% of gulls (N=65 ind.) moved within the wind farm at altitude up to 40 m. There were mostly individuals that separated from flocks feeding on a ground. Raptors Waders Flight altitude (m) > Flight altitude (m) > Number of individuals Number of individuals Passerines Gulls Flight altitude (m) > Flight altitude (m) > Number of individuals Number of individuals All birds species Fig. 3. Approximate flight altitude of migration of raptors, waders, Passerines, gulls and all bird species in autumn Flight altitude (m) > Number of individuals 11

12 3. 5. Mortality of birds caused by collisions with turbines The probability of collision of birds with turbines depends on many different factor. One of the most important is bird species and its age (young birds are most collision-prone), number of birds, their behaviour (most collision-prone are large-size birds intensively using the airspace and little maneuverable species) and weather conditions. The collision risk depends also on field topography and the wind farms location. The collision risk grows in places regularly used by birds, e.g. along coasts where go migration routes, in the neighbourhood of communal roosting places or breeding colonies. The additive factor influencing birds mortality is also the kind of a turbine (mostly its height) and rotor velocity. Their lighting is an additive element decoying birds nearby turbines (especially birds migrating at night) (Langston & Pullan 2003, Drewitt & Langston 2006, Stienen et al. 2008). Some authors (Kikuchi 2008) conclude that collisions especially largesize birds take place usually with towers, and not with rotors. The number of collisions varied between particular wind farms from Europe and outside the continent. Undoubtedly, this depends on the location which in extreme cases causes high number of collisions of breeding birds (breeding colonies of gulls and terns) and migrating (so called bottlenecks in Spain) what contributes a decline of the population number. (Langston & Pullan 2003, Stienen et al. 2007, de Lucas et al. 2007). Many studies indicate that mortality caused by collisions is a main cause of large raptor populations decline (Carrete et al. 2009). The number of collisions revealed for wind farms located in different European countries varied. Mortality of birds for some of farms consisted of turbines (19 turbines near Gnieżdżewo) fluctuates between birds/turbine/year (Everaert 2003). Between only 3 birds from 3 species were found that crashed with working turbines (Table 3). Two species belonged to order of Passerines (a Skylark, a Goldcrest), and one to suborder Laridae (a Black-headed Gull). All these species are protected under the art. 33 par. 1 of Act on Nature Protection. Little number of collisions shown in this period probably results from poor intensive migration and small numbers of birds. In spring, in breeding period and after breeding in 2010 were recorded higher number of collisions than in autumn. Among crashed birds was one dead Skylark - this is the first autumn record of this species which is the most numerous victim during spring and breeding period. Such differences depend on a kind of territorial behaviour based on intensive and long-lasting male singing in a flight what increases the collision risk. However, in autumn Skylarks migrate in a given direction moving quickly throughout the farm area, so the collisions risk is relatively low. Under Dipol turbines 2 birds died due to collisions were found a Goldcrest and a Skylark, and under Łebcz turbines 1 bird a Black-headed Gull (Table 3). The mean distance to the turbine tower which birds were found was 30 m (the range m). The Black-headed Gull probably crashed a few months earlier, because only remains were found (wind bones and feathers primaries, secondaries and covers). However, the Skylark presumably crashed with a turbine a few days before the bird was found. It was eaten in majority by rodents and as a result only the wing was found. The Golcrest had not any visible injuries and was relatively fresh died 2-3 days earlier. Mortality of all birds for all turbines located near Gnieżdżewo was 0.15 bird/turbine for 2-months period ( ). For particular turbines in this period was 0.10 bird/turbine ( Dipol ) and 0.05 bird/turbine for Łebcz turbines. 12

13 Table 3. Dead birds found under turbines near Gnieżdżewo in autumn The date, bird species, turbine number, distance to a tower and direction have been shown. Turbine numbers are consistent with Fig. 6. Date Species Black-headed L. ridibundus Gull NX A. arvensis Skylark EW 07 R. regulus Goldcrest EW 11 Dist. (m) Direction Turbine Łebcz Dipol Dipol G SW NE NE Map 1. The location of dead birds (red colour) found under turbines near Gnieżdżewo in autumn Circles Dipol turbines, squares Łebcz turbines. Digits real signs, letters signs assumed for the purpose of this report. 13

14 The Black-headed Gull Larus ridibundus One Black-headed Gull was found on under the turbine NX Łebcz. Remains of the bird, especially numerous feathers indicate that the gull was in second calendar year of its life (Picture 1, 2), (Map 1), (Table 3) (Baker 1993). Collision presumably took place in summer when searching under Łebcz turbines were not carried out. The Black-headed Gull is in Poland scarce, fairly numerous (Bukaciński et al. 2007). However, during migration this is one of most common species on different kinds of water bodies. Numerous is also in winter, and concentrations from Gdańsk Bay belong to the biggest in Poland (Tomiałojć & Stawarczyk 2003). Black-headed Gulls breed in colonies on fresh-water reservoirs and prefer islands of emergent vegetation or a dry ground. Population breeding in Poland is estimated to thousands of pairs (Chylarecki & Sikora 2007). The nearest colonies are situated a few tens of kilometers to the wind farm. One may assume that the bird that crashed with the turbine used the farm area for foraging or for moving to the fishing port or to the rubbish-dump. The blackheaded Gull is protected: under the art. 33 par. 1 of Act on Nature Protection. not listed in Annex I to EU Birds Directive (Directive EU 79/409/EWG on the Conservation of Wild Birds); not listed in Polish Red Data Book of Animals (Głowaciński 2001). Picture 1, 2. The Black-headed Gull Larus ridibundus found on the turbine NX G Łebcz (photo A. Marchlewski) The Skylark Alauda arvensis The Skylark was found on under the turbine EW07 Dipol (Picture 3), (Map 1), (Table 3). There were only remains (a wind) partially eaten by rodents. Skylarks occur in rural landscape as in breeding period as also outside breeding season. Polish breeding population was estimated to 4-7 millions of pairs and their number was growing in the years (Chylarecki & Jawińska 2007, Tryjanowski 2007). According to the date of remains finding one may conclude that this individual belonged to the population which migrated through the farm area. The Skylark is protected: under the art. 33 par. 1 of Act on Nature Protection. not listed in Annex I to EU Birds Directive (Directive EU 79/409/EWG on the Conservation of Wild Birds); not listed in Polish Red Data Book of Animals (Głowaciński 2001). 14

15 Picture 3. The Skylark Alauda arvensis found on under the turbine EW 07 Dipol (photo A. Marchlewski) The Goldcrest Regulus regulus One young female was found on under the turbine EW 11 Dipol (Table 3), (Map 1), (Picture 4) (Svensson 1992). This individuals had not any injuries caused by a collision. The Goldcrest is a common breeding and migrating bird species. They breed in forests with significant share of Norway Spruce and Silver Fir in the stand. During migration is very numerous, sometimes even invasive (Tomiałojć & Stawarczyk 2003, Wojciechowski & Janiszewski 2007). The habitat preferences of this species indicated that it was migrating individual, not breeding. The Goldcrest is protected: under the art. 33 par. 1 of Act on Nature Protection. not listed in Annex I to EU Birds Directive (Directive EU 79/409/EWG on the Conservation of Wild Birds); not listed in Polish Red Data Book of Animals (Głowaciński 2001). Picture 3, 4. Goldcrests Regulus regulus found on under the turbine EW 11 Dipol (photo A. Marchlewski). 15

16 4. Collisions of bats Between under turbines ( Dipol and Łebcz ) no dead bat was found. Collisions of bats took place only in spring and summer (Report from searching 2010). 5. Intensity of airspace use Intensity of the airspace use in autumn by all birds observed in autumn by all birds observed in a flight was individuals per one hour of a session. The mean number was ind./60 min, and a median 37.2 ind./60 min. The airspace use throughout the autumn varied, but stayed on a low level. In the peak of migration (56-60th 5-day periods) the number of birds recorded during sessions was higher. In the 56th 5-day period, on average were recorded ind./60 min, and in 60th 5-day period on average ind./60 (Fig. 4) Number of individuals/60 min day periods Mean 0.95*Min.-Max. Fig. 4. Intensity of the airspace use by all birds recorded in a flight in autumn Mean intensity (boxes) per 60 minutes of a session, min. and max. (whiskers) have been shown in particular 5-day periods. The airspace use by raptors was in the range 0-7 individual per one hour of a session (Fig. 5). The mean was 1.9 ind./60 min. and a median 0.8 os./60 min. During 13% of sessions were observed no raptor, and during other 87% of sessions were 1-7 individuals. The airspace use throughout the autumn varied. In the 53th and 54th 5-day periods migration stayed on maximum level for this season and was adequately for each 5-day period 4 ind./60 min. and 3 ind./60 min. (Fig. 5). In the 56th 5-day period the number of raptors much fluctuated. Despite mean intensity of the airspace use was low (about 2 ind./60 min), on some days were observed almost 6 ind./60 min. of a session, but on other days were less than 1 ind./60 min. Very similar was the picture of migrations recorded in 59th 5-day period with one difference the mean was almost 4 ind./60 min. of a session, and maximally observed even 7 ind./60 min. Short-term increase of airspace use intensity was noticed also in 61th 5-day period (4 ind./60 min). For analysis of the airspace use were also added individuals that hunted in a flight - especially to Buzzards and Kestrels. The airspace use by particular species from the order of raptors was low due to the numbers that reached these birds. The airspace use by most numerous raptor the Buzzard was on average for all 5-day periods 1.5 ind./60 min. (the median 1.0 ind./60 min). In case of species that crashed in previous years (the White-tailed Eagle, the Kestrel), in autumn these 16

17 birds seldom were observed in a flight, especially the White-tailed Eagle which used the airspace sporadically 0.3 ind./60 min., whereas in spring during one session migrated on average 1.5 ind./60 min. and one died individual was found. The numbers of Kestrels recorded in autumn was 0.7 ind./60 min., similarly as in spring Number of individuals/60 min day periods Mean 0.95*Min.-Max. Fig. 5. Intensity of the airspace use by raptors recorded in a flight in autumn Mean intensity (squares) per 60 minute-session, min. and max. numbers (whiskers) in particular 5- day periods. Because Passerines was the most numerous group recorded in autumn near Gnieżdżewo, the parameters of the airspace use were similar to that estimated for all birds in total. Mean intensity of the airspace use was in the range from 2.6 to ind. per one hour of a session. The mean for all 5-day periods was 92.7 ind./60 min., and the median 26.0 ind./60 min. (Fig. 6). Throughout the whole autumn were recorded three periods when the migration was intensive 53 th, 56 th and 60 th. In the other part of autumn migration was moderate, and the number of birds were not higher than 100 ind./60 min. (Fig. 6). In the 53th as in 56th 5-day periods mean intensity of migration was 200 ind./60 min. There were also recorded high fluctuations of the number especially in 56 th, when were noticed from 5 ind./60 min. to 629 ind./60 min. At the beginning of the migration (60th 5-day period) mean intensity of migration was ind./60 min. In this period were recorded also high differences in the number of migrating birds from 2 ind./60 min. to 502 ind./60 min (Fig. 6). Number of individuals/60 min Fig. 6. Intensity of the airspace use by Passerines in a flight in autumn Mean intensity (squares) per 60 minutes of a session has been shown, min. and max. numbers (whiskers) in particular 5-day periods day periods Mean 0.95*Min.-Max. 17

18 6. Collisions in the years Searching of birds that crashed with turbines took place in two ways. First of them included only spring and autumn migration and was carried out for all turbines ( Dipol, Łebcz ). Second one was a supplementation and was conducted in a breeding period and during post-breeding dispersal only under 11 Dipol turbines. During 4 years of studies under all turbines were found 35 dead birds that crashed with turbines. They belonged to 13 species of a different size from very small to very large the White-tailed Eagle. Most collision-prone species was the Skylark (N=11 ind.), which was found especially in spring and in breeding period - 31% of all crashed birds. The higher number of collisions in breeding period results from very high probability of a collision of displaying Skylarks with working rotors. The next species which often crashed with turbines was the Goldcrest (N=10 ind.) - 28% of all died birds. Collisions of this species took place more often in autumn than in spring (Fig. 7). Among found birds decidedly most valuable was the White-tailed Eagle protected under the art. 33 par. 1 of Act on Nature Protection, listed in Annex I of Birds Directive, Polish Read Data Book of Animals (Głowaciński 2001) and on SPEC list (BirdLife International 2004). Other valuable species was the Kestrel which is scarce and moderately widespread. The Kestrel as other raptors is a collision-prone species due to their long-term using the airspace especially for hunting. Three species the White-tailed Eagle, White Stork and Redbacked Shrike are listed in the Annex I of Birds Directive. During 4 years of monitoring the number of collisions in particular phonological periods varied. The number of collisions differed between spring and autumn migration. However, mortality of birds caused by collision with turbines in the years was growing. This trend is clear even without data from breeding and dispersal periods (Fig. 8). There is no clear differences in the number of died birds between spring (N=15 ind.) and in autumn (N=14 ind.). However, in breeding period were found 3 birds annually. Large-size birds were 20% (N=7 ind.) of all individuals that crashed. Almost all of them (N=6 ind.) crashed with turbines during autumn migration and the only bird from this group found in spring was the White-tailed Eagle. In 2010 mortality of birds near Gnieżdżewo reached the highest number 1 bird/turbine in the period

19 Number of individuals L J W 0 A R FAT HA S PNI EI E LAR CCC FPR LC AB Species Fig. 7. Dead birds found under turbines in the years during spring migration ( ), breeding period, during dispersal ( ) and autumn migration ( ). Red colour spring, green colour breeding and dispersal periods, black colour autumn. R the Goldcrest Regulus regulus, A the Skylark Alauda arvensis, HA the White-tailed Eagle Haliaeetus albicilla, FAT the Kestrel Falco tinnunculus, PNI the Snow Bunting Plectrophenax nivalis, EI the Yellowhammer Emberiza citrinella, E the Robin Erithacus rubecula, HYB the hybrid of the Peregrine and the Gyrfalcon Falco peregrinus x Falco rusticolus, LAR the Black-headed Gull Number of individuals L J W Fig. 8. Changes of the number of birds that crashed with wind turbines in the years during spring migration (black columns), in breeding and dispersal periods (green columns) and in autumn (red columns) near Gnieżdżewo. Dead birds were found at different distances to towers the farther to a tower, the lesser number of birds. Most of birds were found relatively close to towers at a distance m (48%), but also 0-10 m and m (by 20%). The number of birds decreased along growing distance (Fig. 10). Among victims, during a few years of studies were found also small and large size species. Their distances to towers much varied, but the mean distance for small 19

20 birds was 20 m, and for large 30 m. Small birds were in all distance categories to towers. The least distance for this group was 0.5 m, the biggest 50 m. Number of individuals y = -5,4549Ln(x) + 24,515 R 2 = 0, Distance to tower Fig. 10. The breakdown of dead birds in relation to a distance to a turbine. Total numbers of birds (blue squares) in particular categories of a distance were shown and a trend line. 20

21 7. Conclusions 1. Autumn migration near Gniezdżewo (gm. Puck, woj. pomorskie) was poorly intensive. Only 6332 birds from 47 species have been recorded. In the years migrated on average more than 13 thousands of birds in each season. Migrating birds were 61% (N=3894 ind.) and feeding 39% (N=243 ind.). Most numerous were small Passerines (N=3988 ind.), waders (N=723 ind.) and gulls (N=708 ind.). 2. Among birds recorded on the study area predominated Starlings (25%), Golden Plovers (11%), Wood Pigeons (10%) and Jackdaws and Rooks (10%) that migrated in mix species flocks. 3. In total, 20 bird species listed in Annex I of Birds Directive, Polish Red Data Book of Animals and birds classified as SPEC 1 and 2 by BirdLife International. 4. The wind farm location on birds migration route forced change of flight direction omitting particular turbines, omitting the whole of the wind farm by 91 individuals from 6 species only 2% of all birds recorded in flight; Dipol turbines forced avoidance behaviour of 20 ind. from 2 species; Łebcz and Dipol tubines forced avoidance behaviour of 71 ind. from 4 species. - according to surveys carried out in autumn one may assume that the wind farm near Gnieżdżewo has no important deterring effect for migrating birds. This was also confirmed by small number of birds showing avoidance behaviour. 5. Main migration of birds in autumn took place on altitude 0-40 m. In this zone 56% of birds have been recorded. The next altitude zone ( m) were used by 33% of birds. Above working rotors (> 120 m) were observed 11% of birds recorded in flight. 6. In autumn 2010 under all turbines were found 3 birds died due to collision with turbines, belonging to 3 species: the Goldcrest Regulus regulus, the Skylark Alauda arvensis and the Black-headed Gull Larus ridibundus. Mortality of birds resulted from collisions with all turbines near Gnieżdżewo was 0.15 birds/turbine in the period For Dipol turbines mortality was 0.10 bird/turbine (N=2 dead birds); For Łebcz turbines mortality was 0.05 bird/turbine (N=1 dead bird); - in comparison to mortality estimated for other wind farm located in Europe, where e.g birds/turbine/year were recorded (Everaert 2003), the maximum mortality for Gnieżdżewo 1 bird/turbine in 2010 stay on a low level. - the majority of died birds were small species, but 20% of died individuals were large-size birds. Especially valuable of them were White-tailed Eagles (2 died individuals in the years ), Kestrels (2 individuals in 2009), the White Stork (1 individual in 2009). 21

22 7. In autumn between (turbines Dipol and Łebcz ) no died bat was found. Collisions of these mammals took place only in spring and summer. 8. Mean intensity of airspace use by all birds during autumn migration was ind./60 min. Mean intensity of airspace use by raptors was 1.9 ind./60 min. and by Passerines 2.7 os./60 min. 9. In the years birds crashed with turbines that belonged to 13 species. Most collision-prone were Skylarks Alauda arvensis (N=11 ind.) and Goldcrests Regulus regulus (N=10 ind.). 22

23 8. Literatura Akesson S. & Hedenstrom A Wind selectivity of migratory flight departures in birds. Behav. Ecol. Sociobiol. 47: Baker K Identification guide to European non-passerines. BTO Guide 24. London BirdLife International (2004) Birds in Europe: population estimates, trends and conservation status. Cambridge, UK: BirdLife International. (BirdLife Conservation Series No. 12). Bukaciński D., Betleja J. & Zieliński P Śmieszka Larus ridibundus. W: W: Sikora A., Rohde Z., Gromadzki M., Neubauer G., Chylarecki P. (red.) Atlas rozmieszczenia ptaków lęgowych Polski Bogucki Wyd. Nauk., Poznań, s Carrete M., Sánchez-Zapata J., A., Benítez J., R., Lobón M. & Donázar J., A Large scale risk-assessment of wind-farms on population viability of a globally endangered longlived raptor. Biological Conservation 142: Chylarecki P. & Sikora A Ocena liczebności gatunków lęgowych w Polsce. W: Sikora A., Rohde Z., Gromadzki M., Neubauer G., Chylarecki P. (red.) Atlas rozmieszczenia ptaków lęgowych Polski Bogucki Wyd. Nauk., Poznań, s Chylarecki P. & Jawinska D. (2007). Monitoring Pospolitych Ptaków Lęgowych Raport z lat Warszawa: OTOP De Lucas M., Janss G., F., E. & Ferrer M. (2007) (eds.) Birds and wind farms. Risk assessment and migration. Quercus Drewitt A. L. & Langston R. H. W Assessing the impacts of wind farms on birds. Ibis 148: Elkins N Weather and birds behaviour. T&AD POYSER, London Everaert J Wind turbines and birds in Flanders: preliminary study results and recommendations. Natuur. Oriolus 69 (4): Głowaciński Z. (red.) Polska czerwona księga zwierząt - kręgowce. PWRiL, Warszawa. Kikuchi R Adverse impacts of wind power generation on collision behaviour of birds and anti-predator behaviour of squirrels. Journal for Nature Conservation 16: Langston R. H. W. & Pullan J. D Wind farms and birds: an analysis of the effects of wind farms on birds, and guidance on environmental assessment criteria and site selection issues. Strasbourg, Council of Europe, Directorate of Culture and Natural Heritage. Newtom I. (2008). The Migration Ecology of Birds. Academic Press Stienen E. W. M., Courtens W. & Everaert J Sex-biased mortality of common terns in wind farm collisions. The Condor 110 (1):

24 Svensson L Identification guide to European passerines. Stockholm Tomiałojć L. & Stawarczyk T Awifauna Polski. Rozmieszczenie, liczebność i zmiany. PTPP pro Natura. Wrocław. Tryjanowski P Skowronek Alauda arvensis. W: Sikora A., Rohde Z., Gromadzki M., Neubauer G., Chylarecki P. (red.) Atlas rozmieszczenia ptaków lęgowych Polski Bogucki Wyd. Nauk., Poznań, s Wojciechowski Z. & Janiszewski T Mysikrólik Regulus regulus. W: Sikora A., Rohde Z., Gromadzki M., Neubauer G., Chylarecki P. (red.) Atlas rozmieszczenia ptaków lęgowych Polski Bogucki Wyd. Nauk., Poznań, s