Declines amongst breeding Eider Somateria mollissima numbers in the Baltic/Wadden Sea flyway

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Somateria mollissima
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1038.8437

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. creased from ca. 45% (1982) to ca. 25% (2009) and simultaneously the proportion of firstwinter 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.