The Greater Scaup is the only diving duck in the genus Aythya that has a circumpolardistribution. In Alaska this species has its highest nesting densities in the Yukon-KuskokwimDelta but they also breed in Arctic Alaska throughout the Brooks Range, foothills and ArcticCoastal Plain. Its breeding habitat is typically characterized by relatively shallow (1–2 m) lakesand large ponds with low surrounding vegetation in extensive, largely treeless, wetlands (Kesselet al. 2002). Greater Scaup have an omnivorous diet but tend to focus on more protein-richanimal foods (mostly aquatic invertebrates) during the summer. This species winters primarily inmarine waters of both the Atlantic and Pacific coasts (Kessel et al. 2002). Breeding groundpopulation estimates for this species from 1978-2011 range from 434,000 – 642,000 and there issome evidence of regional declines (Kessel et al. 2002).
