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.
Similar Species- Greater Scaup, Ring-necked Duck
Easily remembered as repeatedly calling: scaup.
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.
During migration and when not breeding, found along 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.
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.
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.
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.
No references are available at this time.