Declining populations of Long-tailed Duck and Common Eider
The breeding population of Common Eiders, especially from mid-Norway to the Lofoten area, as well as wintering populations of both Common Eider and Long-tailed Duck, are in heavy decline. This is revealed in a report evaluating the condition of breeding and winter populations for some of our marine diving ducks (Greater Scaup, Common Eider, Long-tailed Duck, Common- and Velvet Scoter) in Scandinavia and Island.
The report, compiled by Norwegian, Finnish, Swedish, Danish and Islandic researchers, also concludes that the winter population of Great Scaup, Common- and Velvet Scoter are declining in the Bothnian Bay, whereas the situation seems to be stable for these species in Norwegian waters. All of the marine diving ducks studied subsist on mussels, especially Blue Mussels. The report discusses several possible causes of the decline in the duck populations, but overall, the main driver of the decline remains unclear. The report concludes that more research is needed, especially regarding vital rates (particularly adult survival and breeding success) and factors driving changes in the food availability for these species.
Read the report:
Contact person: Svein-Håkon Lorentsen, NINA
Photo: Sébastien Descamps