| 1. |
- Ekroos, Johan, et al.
(författare)
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Declines amongst breeding Eider Somateria mollissima numbers in the Baltic/Wadden Sea flyway
- 2012
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Ingår i: Ornis Fennica. - 0030-5685. ; 89:2, s. 81-90
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Tidskriftsartikel (refereegranskat)abstract
- We report on the status of the Baltic/Wadden Sea flyway Eider population based on trends in breeding and wintering numbers throughout the region, supplemented by changes in the sex ratio and proportion of young Eiders as monitored in the Danish hunting bag. At the flyway scale, total numbers of breeding pairs decreased by 48% during 2000-2009, after relatively stable breeding numbers in 1991-2000. The majority of the population nest in Finland and Sweden, where the number of breeding pairs has halved over the same period. After initial declines in winter numbers between 1991 and 2000, during 2000-2009, national wintering numbers increased in the Baltic Sea, but decreased in the Wadden Sea. The annual proportion of adult females in the Danish hunting bag data decreased from ca. 45% (1982) to ca. 25% (2009) and simultaneously the proportion of first-winter birds fell from ca. 70% to ca. 30%, indicating dramatic structural changes in the Danish wintering numbers. These results suggest that the total flyway population will experience further declines, unless productivity increases and the factors responsible for decreasing adult female survival are identified and ameliorated. We discuss potential population drivers and present some recommendations for improved flyway-level monitoring and management of Eiders.
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| 2. |
- Marchowski, Dominik, et al.
(författare)
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Effectiveness of the European Natura 2000 network to sustain a specialist wintering waterbird population in the face of climate change
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Analysis of coordinated Greater Scaup (Aythya marila) count data from the last 30 years showed a 38.1% decrease in wintering numbers in North-West Europe, from 309,000 during 1988–1991 to c.192,300 individuals during 2015–2018. Annual trends in wintering numbers differed throughout the range. Numbers decreased in the UK, Ireland, and in the Netherlands, while numbers were stable in Denmark. Germany, Poland, Sweden, and Estonia showed increasing numbers, suggesting a shift in the distribution of the species within its wintering grounds towards the east and north. Higher temperatures in northern and eastern areas were correlated with the range shift of the wintering distribution. Deaths from bycatch drowning of Scaup in fishing gear have significantly decreased in recent decades in the Netherlands, where currently the greatest threat is considered the deterioration of food resources. The increasing concentration of wintering Scaup in coastal Poland and Germany (where lack of effective implementation of conservation measures fail to protect the species from the impacts of bycatch and declining food quality) pose major threats to the entire population.
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