The Lesser Scaup is a common North American diving duck that gathers in large flocks on lakes and bays. Its head often has a small peak near the back, a useful clue when comparing it with the similar Greater Scaup (Aythya marila).
Appearance
Appearance
Males have dark heads and chests, gray backs, and white sides. Females are brown with a white patch beside the bill. The head often peaks near the rear, but its shape changes as the bird moves and dives.
Greater Scaup usually have a smoothly rounded head. In a wing-spread photo, their white wing stripe reaches farther toward the wingtip than a Lesser Scaup's. A distant resting bird may be impossible to settle from one photo.
A male Ring-necked Duck (Aythya collaris) has a dark back, a white mark rising at the front of the side, and pale rings on the bill. A male Lesser Scaup has a gray back and lacks those bill rings.
Where it lives
Typical habitats
Prairie wetlands
Lakes and reservoirs
Coastal bays
Range
It breeds in the northern U.S. , Alaska, and Canada. During migration and winter, it uses lakes, reservoirs, and coastal waters across the U.S.
Seasonal presence
In many U.S. states, it is easiest to find during migration and winter.
Behavior
Diet
It dives for small aquatic animals, including , insects, and , and also eats aquatic plants and seeds.
Social life
Outside the breeding season it gathers in flocks, often with other diving ducks.
Life cycle
Nest
The female hides a ground nest among tall wetland plants, sometimes on floating vegetation.
Clutch size
6–14 eggs
Incubation
21–27 days
Conservation
IUCN Red List
LCLeast Concern·Low risk of extinction
Status
North American breeding survey counts declined slightly over 1966–2019.