Aythya affinis

Lesser scaup pair. ©DUC

Traditionally, lesser scaup (a.k.a. blue bill) have been one of the most abundant ducks in North America; however, over the last 20 years, the duck population has spiraled downward.

Appearance

  • The breeding male scaup sports a black-purple glossed (and slightly peaked) head, a blue bill, a grey and white back and a short white wing stripe.
  • The drab brown female has a white face patch around her bill and a short white wing stripe.

Breeding

  • Lesser scaup begin courtship in December, continue through spring migration and are paired by the time they reach their breeding grounds.
  • The average clutch size is nine eggs and incubation lasts between 21 and 27 days.
  • Ducklings can walk, swim and dive almost immediately.
  • Broods will sometimes create large groups with many ducklings.
  • Ducklings are able to fly at 47 days.

Habitat: Wetlands with large quantities of submergent and emergent vegetation, which are important for feeding, nesting and cover.

Range: Lesser scaup start moving north from their wintering grounds in the southern U.S. in February. They arrive on their breeding grounds from Alaska, B.C., across the Canadian prairies and into the northern Great Plains of the U.S. from late March to early June. In the fall, they are some of the last ducks to venture south.

Diet: They make short dives for food. Food is either taken from the water column or by shovelling through soft bottom substrates. They feed on aquatic invertebrates like amphipods, midges, clams, snails and zebra mussels in the early breeding season and seeds from aquatic plants in the late summer.

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