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

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Red-breasted Merganser Mergus merganser The Red-breasted Merganser was the most numerous species during most surveys in the study area north of Falsterbo, with the exception of some surveys in spring, when the Eider was more numerous. The majority of the Red-breasted Mergansers seen during the aerial surveys were found in the areas north of Falsterbo (Table 3, Fig. 26). Within this area Mergansers were concentrated to the parts between Bredgrund and the Öresund Bridge, i.e. the five northernmost aerial transects. The study area covered by the aerial surveys is the most important wintering area in Sweden and the Baltic for the species. The total numbers occurring here has been estimated to be in the order of 10-12 000 individuals which should be compared with that the total Baltic wintering population is estimated to consist of around 26 000 individuals and that the entire northwest European wintering population is estimated to 170 000 individuals (SOWBAS). This means that 38-46 % of the total Baltic wintering population use this area in winter (6-7 % of the overall northwest European population). Hence, southern Öresund is of large international importance for the species. The majority of the Red-breasted Mergansers arrive in the area during late autumn and leave relatively early in spring. At most surveys in early autumn and in April-May, only small numbers are found in the area. The distribution maps show fewer Red-breasted Mergansers within the wind farm area with the farm in operation than during the pre-construction period, especially during the first years after the construction of the farm (see maps in appendix). Calculated densities decreased in all sub-areas from the pre- to the post construction period (Fig. 32). With the wind farm in operation densities were rather similar in all sub-areas while densities were distinctly higher in the buffer zone and the parts of the northern study area being farthest from the wind farm in the pre-construction years (Fig. 32). Within the wind farm area the density was only slightly lower in the post-construction period than before this. The mean number counted within the windfarm area during the three surveys in the winter 2006 (preconstruction) was eleven as was also the case for the three surveys in 2011, with smaller numbers in the intervening years. Mean numbers counted within the survey lines in the buffer zone varied between 31 and 171, whereas means for the outer reference area varied between 165 and 873. For annual means see Table A10 in the appendix. Numbers counted during the spring surveys were too low for the calculation of densities. 48
2500 2000 1500 1000 500 0 MIN MEAN MAX Mergus serrator BEFORE AFTER BEFORE AFTER SOUTH NORTH Fig. 27. Mean, Maximum and Minimum counts of Red-breasted Merganser Mergus serrator during aerial surveys in the northern and southern area (Fig. 5) pre- (7 counts) and post- (15 counts) construction of the wind farm at Lillgrund. Medel, maximum och minimum antal av småskrake Mergus serrator i det norra och södra området (Fig. 5) före (7 räkningar) och efter (15 räkningar) uppförandet av vindkraftparken på Lillgrund. 3000 2500 2000 1500 1000 500 0 Mergus serrator MIN MEAN MAX BEFORE AFTER Fig. 28. Mean, Maximum and Minimum counts of Red-breasted merganser Mergus serrator at boat surveys (Fig. 3) pre- (19 counts) and post- (8 counts) construction of the wind farm at Lillgrund. Medel, maximum och minimum antal av småskrake Mergus serrator vid båtinventeringar (Fig. 3) före (19) räkningar) och efter (8 räkningar) uppförandet av vindkraftparken på Lillgrund 49
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 41 and 42: Common Eider Somateria mollissima T
Page 47: Jacobs Index Jacobs Index 1 0,5 0 -
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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