Greater Scaup

Read about the Scaup and Mallard Ducks!

The Greater Scaup

Latin: Aythya marila
Average length: M 18.6", F 17"
Average weight: M 2.32 lbs., F 2.15 lbs


Male greater scaup have a glossy black head tinted green. The neck, breast and upper mantle are glossy black, and the flanks and belly are white, usually with gray irregular line patterns on the lower flanks. The back is whitish with fine black lines, and the tail is black. The bill is a light blue-gray with a black nail, the legs and feet are gray and the eye is yellow. The male greater scaup utters a soft cooing and whistling notes in but are otherwise silent. The female greater scaup are brown with white oval patches around their bills. The female's bill is similar to that of the male, but slightly duller, and the legs and feet are gray.


The greater scaup breeds on the tundra and in the boreal forest zones from Iceland across northern Scandinavia, northern Russia, northern Siberia and the western North American Arctic. It is estimated that three-quarters of the North American population breeds in Alaska. They lay an average of 9 eggs.

Greater scaup migrate across the boreal forests of Canada prior to reaching their wintering grounds along the Atlantic coast or from Alaska to their wintering grounds along the Pacific coast.


Greater scaup dive to feed on aquatic plants and animals. This is known as dabbling. In coastal areas, mollusks make up main diet. In freshwater habitats, seeds, leaves, stems, roots and tubers of aquatic plants are eaten.

Mallard Duck Plumage

The mallard usually has the plumage shown in the picture above, however, they go through a period called eclipse plumage when they molt after breeding.

When their primary feathers are molting, they are largely flightless and tend to be very reclusive. Mallard drakes in eclipse plumage still have the green iridescent head, but it is much scruffier and mixed with dark or buff feathers. While the overall color of an eclipse mallard's breast remains the same chestnut color, in this type of plumage it will be mottled with a spotted or scaled pattern similar to the pattern of a female mallard's more camouflaged plumage. Overall, mallards in eclipse plumage often look scruffy or tattered. Some of their feathers may be missing while others have size differences that keep them from aligning smoothly. As the bird's old, worn feathers are replaced with fresh feathers, the plumage will smooth out.