The Greater Scaup, Aythya marila, drake has a black chest and rump, white flanks and undersides. Its back is grayish. It has a large rounded head with a greenish tinge. Its bill is light gray. The hen has a brown head and breast and white at the base of its gray bill.
The Greater Scaup can easily be confused with its cousin the Lesser Scaup, which are nearly identical in the field except for the wing marks. The Greater breeds primarily in the far north on tundra lakes and ponds.
The light band near the trailing edges of the wings runs almost to the tip in the greater scaup, but only about half way in the lesser. Greater scaup prefer large open water areas; lesser scaup often use marshes and ponds.
Both species migrate late, sometimes just before freezeup. Flock movements are rapid, often erratic, usually in compact groups.
Length: 18 1/2"
Weight: 2 lbs.
Hens are silent; drake lesser scaup purr; drake greater scaup have a discordant scaup, scaup.