Lesser Scaup

Aythya affinis (Eyton, 1838)

38–48 cmLength73 cmWingspan820 gWeight

This is a small diving duck; the male in breeding plumage has a glossy black head and a blue-gray bill with a small black tip.

Busiest months: March–April · Most records: United States, Canada, Mexico

Looks like Greater Scaup, Ring-necked Duck

Least Concern

How to identify

Field marks

Male in breeding plumage has an iridescent black head with a tuft at the rear
Male in breeding plumage has a black breast, grayish-white back and white underparts
Bill blue-gray with a black “nail” at the tip
Secondaries white in flight

Male, female and young

Female dark brown with a white band at the base of the bill; juvenile resembles female but is duller, with almost no white at the base of the bill; male has a bright yellow iris, female orange to yellow.

Voice

Quieter than dabbling ducks. Female gives a grating “scaup” call; more vocal than female Greater Scaup, especially in flight, but with a weaker, throaty “brrtt, brrtt”.

Similar species

Greater Scaup

Often difficult to distinguish without direct comparison; this species usually has a smaller, straighter bill and white secondaries in flight, while the white in Greater Scaup extends onto the primaries.

Ring-necked Duck

Males in breeding plumage may be almost identical in size and shape, but Ring-necked Duck has a black back and wings, whereas those of male Lesser Scaup are paler.

Where and when it's recorded

Busiest months: March–April · Most records: United States, Canada, Mexico

Lesser Scaup has been recorded at 1,068 of the 8,276 birding hotspots we track, in 55 countries and regions.

Records by month Northern Hemisphere

Where it's recorded most

Riparian Preserve at Gilbert Water RanchUnited States7,897 records
Hornsby BendUnited States7,471 records
Bolsa Chica Ecological ReserveUnited States7,184 records

More places

Reifel Bird SanctuaryCanada7,020 records
Philomath Sewage PondsUnited States6,537 records
Riverlands Migratory Bird SanctuaryUnited States5,442 records
Tommy Thompson ParkCanada5,145 records
Muskegon Wastewater SystemUnited States4,871 records
Iona IslandCanada4,213 records
Henderson Bird Viewing PreserveUnited States4,162 records

Countries and regions with the most records

United States Canada Mexico Costa Rica Belize Honduras Bermuda Cayman Islands

eBird records via GBIF up to 2024-12-31. A record means someone listed it; more records partly mean more birders, not more birds.

About

The lesser scaup (Aythya affinis) is a small North American diving duck that migrates south as far as Central America in winter. It is colloquially known as the little bluebill or broadbill because of its distinctive blue bill. The origin of the name scaup may stem from the bird's preference for feeding on scalp—the Scottish word for clams, oysters, and mussels; however, some credit it to the female's discordant scaup call as the name's source.

Excerpt from Wikipedia, CC BY-SA 4.0 · authors · Read more on Wikipedia

Questions

How big is the Lesser Scaup?

The Lesser Scaup is about 38–48 cm long, with a wingspan of 73 cm and weighs around 820 g.

Where does the Lesser Scaup live?

Its breeding range: North America: southwestern Alaska mainland to California, west-central Quebec and western Minnesota. It is most often recorded in United States, Canada and Mexico.