Birds in southern Öresund in relation to the wind farm at ... - Vattenfall

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Jacobs Index Jacobs Index 0,5 0 -0,5 -1 1 0,5 0 -0,5 -1 2001- 2002 Aerial 2006 2008 2009 2010 2011 2002- 2003 2003- 2004 Boat 2005a 2005b 2007- 2008 40 2009- 2010 2010- 2011 Fig. 19. Variation in Jacob’s index (see text for explanation) between years (centered around mid-winter for boat data) for Long-tailed Ducks Clangula hyemalis based on aerial (top) and boat survey (bottom) data. Indices from the pre-construction period are shown with open symbols and broken lines, indices from the post-construction period with filled symbols and full lines. Red = the wind farm area, Blue = the buffer zone, up to 2 km from the wind farm. 2005a = winter-spring 2005, 2005b = autumn-winter 2005. Note that no Long-tailed Ducks were seen at all during boat surveys in 2009-2010. Hence, no Jacob’s index can be calculated for this year. Variation i Jacobs index (se text för förklaring) mellan år (centrerade runt midvinter för index från båtdata) för alfågel Clangula hyemalis vid flyg (överst) och båtinventeringar (underst). Index från före vindkraftparken byggdes visas med ofyllda symboler och streckade linjer, index från perioden med parken i drift med fyllda symboler och heldragna linjer. Röd = vindkraftparken, blå = buffertzonen upp till 2 km från parken. 2005a = första halvåret 2005, 2005b = andra halvåret. Notera att inga alfåglar alls sågs under båtinventering 2009- 2010 varför inga Jacobs index kan beräknas.
Common Eider Somateria mollissima The aerial surveys and the boat counts show marked variations in the number of Eiders in the area (Fig. 20 & 21). Maximum counts were between 7000 and 8000 both for the parts covered by the boat counts and the southern area covered by aerial surveys. Eiders are regularly wintering in southern Öresund with the largest concentrations in the waters south of Falsterbo, where estimated numbers regularly are between 10 000 and 15 000 individuals (Nilsson unpubl.). Wintering flocks are also found north of Falsterbo, but there the numbers present are usually lower. In spring, during the migration period, the distribution of Eiders is markedly different from the winter distribution with large flocks both in the waters north of Falsterbo and in the reference area south of Falsterbo (Fig. 22). Large flocks of migrating Eiders are regularly found resting both in the Öresund proper and in the waters south of Falsterbo during this time of the year. Moreover, the breeding colony at Saltholm with between 4000 and 5000 pairs in 2000 (Desholm et al. 2002) is situated a short distance to the north of Lillgrund and probably these birds use the shallow areas also on the Swedish side of Öresund for foraging. Regular movements of pairs and small groups of Eider between Saltholm and the waters around Bredgrund and Lillgrund were observed during studies of in the area around the bridge (Nilsson et al. 2009, 2010). In May, three flights in 2006, 2008 and 2009 showed that the majority of the Eiders were at this time in the northern area. In May most of the migration has passed and the majority of the Eiders counted were probably local birds, mainly from the Saltholm colony. The majority of those late Eiders were males, as the most of the females were incubating at this time. There were marked differences in the local distribution of the Eiders in the Lillgrund area when comparing the pre- and post-construction years (Figs 22, 23, 24). The density of Eiders was markedly higher in the wind farm area before the construction of the wind farm than anywhere else in the northern study area, both in spring and in winter (Fig. 25). Postconstruction the densities in the wind farm area were much lower, while densities in the 2 km buffer zone instead were higher than during the pre-construction period. The maps (Fig. 21, 22, 23) and the densities (Fig. 24) hence indicate a shift in the local distribution from the wind farm area to adjacent parts of Lillgrund and its surroundings. Number of Eiders counted in the aerial surveys showed much variation between years in all zones (Table A10, appendix). In winter mean numbers varied between 1 and 22 Eiders within the windfarm area. In spring high counts were obtained in 2006 (before) and 2011 (last year of study) with 296 and 280 Eiders counted, respectively. In the buffer zone mean numbers counted in the survey lines varied between 26 and 327 in winter and between 391 and 1118 in spring. 41
Page 1 and 2: Birds in southern Öresund in relat
Page 3 and 4: Contents Summary 4 Svensk sammanfat
Page 5 and 6: the birds and/or the flocks, the be
Page 7 and 8: Metoder Inventeringarna av rastande
Page 9 and 10: Alfågel (Fig. 14-19) Alfågeln öv
Page 11 and 12: Liksom vid andra inventeringar av r
Page 13 and 14: Introduction Southern Öresund is a
Page 15 and 16: Lillgrund is situated in the southe
Page 17 and 18: had to be made with only one observ
Page 19 and 20: Fig. 5. Map of the southern part of
Page 21 and 22: Fig. 6 . Map over the wind farm at
Page 23 and 24: transect was divided into 10 km lon
Page 25 and 26: Results Staging and wintering birds
Page 27 and 28: Table.3 Percentage of the total num
Page 29 and 30: Cormorant Phalacrocorax carbo As is
Page 31 and 32: Fig. 10. Summary distribution maps
Page 33 and 34: Overall Jacob’s index (D) for the
Page 35 and 36: Long-tailed Duck Clangula hyemalis
Page 37 and 38: ehind the large variation is that f
Page 39: Fig. 17. Summary distribution maps
Page 47 and 48: Jacobs Index Jacobs Index 1 0,5 0 -
Page 49 and 50: 2500 2000 1500 1000 500 0 MIN MEAN
Page 51 and 52: Fig. 30. Details of Fig. 29 to show
Page 53 and 54: large-scale changes in abundance ar
Page 55 and 56: 600 500 400 300 200 100 0 MIN MEAN
Page 59 and 60: Jacobs Index Jacobs Index 1 0,5 0 -
Page 61 and 62: Lillgrund and the wind farm are sit
Page 63 and 64: The spring migration season, and he
Page 65 and 66: % of all echoes (flocks) 45 40 35 3
Page 71 and 72: irds given the assumptions used abo
Page 73 and 74: % of all echoes (flocks) % of all e
Page 75 and 76: % av alla ekon (flockar) 20 15 10 5
Page 77 and 78: species, some species being better
Page 79 and 80: area and from a Dutch farm show tha
Page 81 and 82: distance from the farm, although mo
Page 83 and 84: Literature Alerstam, T. 1972. Noctu
Page 85: Petersen, I. K. & Fox A. D. 2007. C

Birds in southern Öresund in relation to the wind farm at ... - Vattenfall

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