Nest-Site Selection, Interspecific Associations, And Nest Success Of King Eiders

We investigated factors influencing nest success in King Eiders (Somateria spectabilis) at Karrak Lake, Nunavut, Canada, during 1995-2001. Island-nesting King Eiders had higher nest success (range 30-89%) than that reported for main I and-nesting populations, and nested at much higher densities (46-198 nests km(-2)) than on mainland, where they were detected infrequently (usually <1 nest km(-2)). Predation was the main cause of nest failure, and King Eider nest success was greater on isolated islands (smaller islands, and larger islands farther from the mainland) that were presumably less accessible to mammalian predators. King Eiders did not derive protection from predators by nesting near gulls (Larus spp.) and Arctic Terns (Sterna paradisaea).