Lesser Scaup

Identification

The lesser scaup is a small diving duck measuring 38–48 cm in length with a wingspan of 68–78 cm. Males are noticeably heavier than females, averaging 820 g compared to 730 g. Both sexes share the species' most distinctive feature: a blue-grey bill with a small black "nail" at the tip, earning the bird its colloquial name "little bluebill" or "broadbill."

Adult males in breeding plumage display striking contrasts: a glossy black head with a small tuft at the hindcrown, black breast, and whitish-grey back, with white underparts and black tail. Females and non-breeding males are dark brown overall, shading to white on the mid-belly, with a diagnostic white band at the base of the bill. Males have bright yellow eyes, while females have orange to yellow eyes. In flight, the white secondary feathers are a key identifying feature, extending only partway along the wing—unlike the greater scaup, with which they often overlap in range. When observing birds at rest, the lesser scaup's distinctive head shape—with a less bulging forehead and a strongly curved nape—helps distinguish it from its larger relative.

Range & Habitat

The lesser scaup is a North American species that undertakes significant seasonal migrations. Breeding populations occupy northern regions, and the species migrates southward in winter, with some birds traveling as far as Central America. This migratory pattern means that observing lesser scaup depends heavily on the season and location.

Behaviour & Diet

As diving ducks, lesser scaup feed by submerging underwater to reach food sources. The species name reflects their traditional diet: "scaup" may derive from "scalp," a Scottish word for clams, oysters, and mussels. These birds are relatively quiet compared to dabbling ducks, though females vocalize more frequently than their greater scaup counterparts, particularly during flight, producing a weak, guttural call. Males produce soft whistles during courtship displays.

Best Time & Places to See It

Lesser scaup are most readily observed during migration periods and winter months, particularly in open water habitats including lakes, reservoirs, and coastal areas. In North America, large scaup flocks often contain both lesser and greater scaup species, offering opportunities for comparison and study. Winter concentrations in southern regions and along migration corridors provide the best viewing opportunities.

Photography Tips

Photograph males in breeding plumage for the most striking images, capturing their iridescent black heads and contrasting white underparts. The bird's small head tuft is most visible when the duck raises its head, so patience and timing are essential. Capture birds in flight to showcase the diagnostic white secondary feathers. When comparing with greater scaup, photograph the head shape profile and bill proportions—the lesser scaup's smaller, straighter bill and distinctly curved nape crest are key identifying features. Backlighting can help reveal plumage details and the delicate vermiculations on the wings and flanks.