Local movements, home ranges and body condition of Common Eiders Somateria mollissima wintering in Southwest Greenland.

We examined local movements, home ranges and body condition of wintering Northern Common Eiders Somateria mollissima borealis in Southwest Greenland from late winter until spring migration in 2000 and 2001. At key marine habitats at coastal areas and in the inner fjord system of Nuuk, we implanted 33 Eiders with satellite transmitters and collected Eider carcasses for body condition analyses. Most Eiders exhibited strong site fidelity during the study period with a mean 95% home range size of 67.8 km2 and a mean core area (50%) of 8.1 km2. Diurnal movements peaked at dawn and dusk when birds presumably moved between feeding areas and roosting sites. Roosting occurred near daytime activity centres, on average 1.7 km apart. Among birds marked at coastal habitats only between 8% and 29% also used the inner fjord habitats, despite high levels of hunting at the coastal area. Birds that did move to the inner fjord system did not return to the coastal area

Merkel F.R., Mosbech A. et al., ARDEA 94 (3): 639-650.