Description:

The Lesser Scaup is a medium-sized diving duck. Slight bump or peak on back of head. Bill bluish with small black tip. Male with black head, chest, and rear end, and gray sides (black on the ends and white in the middle). 15-18 1/2" (38-47 cm). Dark brown breast, rump, tail, and head with yellow eyes; bluish gray bill with black tip. Gray scaled back; white flanks. Females have brown mottled flanks, brown breast, and white facial patch at base of bill. Wingspan: 68-78 cm (27-31 in). Weight: 454-1089 g (16.03-38.44 ounces).

Habitat:

During migration and when not breeding, these ducks are found along the coast in sheltered bays, estuaries, and marshes, or inland on lakes, ponds, and rivers; found on saltwater especially if lakes and ponds are frozen. In southern winter range, prefers freshwater ponds, lakes, and sloughs with reasonably clear water 1 m or more deep.

Behavior:

Outside of the breeding season, Greater Scaup form large flocks or rafts, numbering in the thousands. In tidal waters, they tend to face up-current. While individuals may drift downstream, birds from the back of the flock fly to the front, maintaining the raft in the same position. A diver, the Greater Scaup catches its food under water, but eats it on the surface. Occasionally scaups forage at or near the water’s surface as well.

Diet:

Diet consists of about equal amounts of plant and animal food. Feeds on seeds of pondweeds, wigeon grass, wild rice, sedges, and bulrushes. Also eats crustaceans, mollusks, and aquatic insects.

Nesting:

Egg-laying begins early May in sourthern range, to mid-June in north. clutch size varies from 6-15 eggs, but is usually 9-12 (older females lay largest clutches). Female incubates eggs (incubation lasts 22-27 days) and tends young. A variable percentage of yearling females do not breed.

Distribution:

Breeds from Alaska and parts of Canada, south to northern Idaho, northern Wyoming, northern North Dakota, and Minnesota, and casually or irregularly to western Washington, northeastern California, southern Idaho, northeastern Colorado, and parts of Midwest. Winters from southern Alaska, east to New England, and south through southern Idaho, Utah, northeastern Colorado, parts of Midwest, and southern U.S., to northern Colombia.

Feeds mostly in freshwater 1-2 m deep. Builds nest on ground, close to water; occasionally nests over water. In Idaho, prefers marshes for nesting, and open reservoirs and large rivers during migration and in winter.