The Greater Scaups (Aythya marila) – commonly referred to as Scaup in Europe or “Bluebill” – is a small diving duck. It got its name from “scalp” – a Scottish and Northern English word for a shellfish bed (“probably” the same word as the scalp of the head), or from the duck’s display call scaup scaup.
Distribution / Range:
The Greater Scaups (Aythya marila) breeds on the ground by lakes and bogs on the tundra and at the northern limits of the boreal forest across Arctic and subarctic regions of northern North America, Europe, and Asia.
Greater Scaup migrate southwards to winter in flocks to coastal waters.
In North America, Greater Scaup populations have been on a steady decline since the 1990’s. Biologists and conservationists are unsure of the reasons for the decline. Some researchers believe a parasitic trematode found in snails may be to blame.
The Greater Scaup is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.
Diet / Feeding:
The Greater Scaups mainly eat mollusks and aquatic plants, obtained by diving and swimming underwater. There is a report of four Greater Scaups swallowing leopard frogs (with body length about 5 cm (2 inches) which they dredged out of a roadside freshwater pond.
The Greater Scaup averages 42–51 cm in length and has a wingspan of 71–80 cm. It is larger than the Lesser Scaup.
It has a blue bill and yellow eyes.
The adult male‘s head is dark (nearly black) colored head with a green sheen, a black chest, a light back, a black tail, and a white bottom.
The adult female has a brown body and head – with a white band at the base of the bill.
Calls / Vocalizations
The Great Scaup is mostly silent when not breeding.