The greater scaup is a large diving duck and one of the few circumpolar duck species that can be found in both North America and Eurasia. This bird can also be one of the most challenging ducks to identify, however, because of its similarities to the lesser scaup.

Common Name:

Greater Scaup, Scaup

Scientific Name:

Aythya marila

Appearance:

• Bill: Blue-gray, large black nail
• Size: 18-20 inches long with 32-inch wingspan, round head

• Colors: White, black, gray, iridescent, brown
• Markings: Dimorphic species. Males have a black head, neck and breast that may show green iridescence. The white back is finely barred with black and the flanks and abdomen are white, though on some birds very minimal barring extends onto the flanks. The rump, tail and undertail coverts are black. Wings have a white stripe on the primary and secondary feathers that is visible in flight and may show minimally at rest. Females are allover brown, darker above and a mottled blur with gray below. Females have a white belly and a white patch at the base of the bill. Both genders have yellow eyes and gray or black legs and feet.

Foods:

Aquatic plants, aquatic insects, mollusks

Habitat and Migration:

Greater scaups prefer large bodies of water such as lakes, bays and coasts, and they’re most frequently found in marine environments. Their summer range includes northern Canada and Alaska as well as Siberia and the northern reaches of Europe. In winter, these birds can be found along appropriate coasts and on large inland lakes in North America, Europe and northern Asia.

They can be found year-round in the Aleutian Islands.

Vocalizations:

These are generally quiet birds, though males will use a soft, quick whistle to attract females’ attention during courtship. Female greater scaups have a raspy “arrr-arrr-arrr-arrr-arrr” call that stays on a single pitch.

Behavior

Greater scaups are social birds that form huge colonies in winter, primarily in marine and coastal locations. They also form large groups during migration and annual molting periods, and they may even nest in colonies. As diving ducks, they are accomplished swimmers and feed while swimming underwater.

Reproduction:

Greater scaups are monogamous and a mated pair will raise a single brood of 6-10 eggs annually. The female parent incubates the eggs for 25-27 days, and the precocial young are able to leave the nest as soon as they are dry from hatching. While the young birds can feed themselves, the females continue to lead them to food and care for them for 36-40 days until their first flight.

Attracting Greater Scaups:

Like most ducks these are not backyard birds, but birders can find them in appropriate habitats mostly in winter. Because greater scaups form large colonies they can be very visible, but individual birds can also appear in mixed flocks with other types of ducks and it is prudent to check each bird in a flock for different species.

Similar Birds:

• Lesser Scaup (Aythya affinis)
• Ring-Necked Duck (Aythya collaris)
• Tufted Duck (Aythya fuligula)

Photo – Greater Scaup – Male © Greg
Photo – Greater Scaup – Female © Jean