General

Greater Scaup: Large diving duck with glossy green-black head, white sides and belly, black tail, neck, breast and barred gray flanks and back; wing coverts black tinged with brown, speckled with white, broad band over secondaries and most primaries; underwing and axillaries white. Female brown overall; white ear patch; some white on mantle, scapulars and flanks; wings more brown; bold white patch at base of black-tipped gray bill. Juvenile resembles female, is duller overall with less white on cheeks and face, darker brown head and gray bill.

Range and Habitat

Greater Scaup: Breeds within the Arctic Circle, both in the Palearctic and North America. Also found in Asia, and is present in the Aleutian Islands year round. Spends the summer breeding in Alaska, Canada, Siberia, and northern Europe. In winter, it migrates down the coasts of North America, Europe, and Japan. Prefers ponds, marshes and lakes.

Breeding and Nesting

Greater Scaup: They breed on the tundra and in the boreal forest zones from Iceland across northern Scandinavia, northern Russia, northern Siberia and the western North American Arctic. They build a nest of decaying plant material and down close to or floating on the water. Five to eleven dark olive buff eggs are incubated by the female for 24 to 28 days. They have one brood per year.

Foraging and Feeding

Greater Scaup: Their diet includes small bivalves, snails, mollusks, crustaceans, aquatic insects and larvae, and seeds and vegetative parts of aquatic plants, obtained by diving and swimming underwater. They are primarily a diurnal feeder, but tend to shift to nocturnal feeding in the fall and winter if disturbed by recreational small-boat traffic, especially hunting and fishing activities.

Vocalization

Greater Scaup: Usually silent but can utter a loud "scaup." Breeding males make a soft "week, week, week" sound.

Similar Species

Greater Scaup: Lesser Scaup is smaller, has a peaked crown, and grayer sides.