The lesser scaup is believed to be the most abundant diving duck in North America, but it can be hard to distinguish from its near-twin, the greater scaup. Birders who are familiar with both species, however, can learn to distinguish the minute characteristics that separate them.
Common Name:
Lesser Scaup, Bluebill
Scientific Name:
Aythya affinis
Appearance:
- Bill: Blue-gray, black nail
- Size: 16-18 inches long with 26-32-inch wingspan, peaked head
- Colors: Black, gray, blue, brown, white, iridescent
- Markings: Dimorphic species. Males have a black breast, head and neck that may show purple iridescence in good light. The white body has moderate gray or black barring on the back that extends onto the flanks. The rump, tail and undertail coverts are black. Females have a dark brown head and neck with a white patch at the base of the dark bill. The back, chest and flanks are a mottled grey and brown, and the rump and undertail coverts are brown. Both genders have bright yellow eyes.
Foods:
Aquatic plants, invertebrates, aquatic insects
Habitat and Migration:
Lesser scaups prefer freshwater habitats such as lakes, rivers and marshes, though in winter when freshwater areas freeze they can be found in marine habitats. These ducks have an extensive North American range, which in summer includes Alaska and all of Canada, as well as northern regions of Idaho, Montana, North Dakota and Colorado. The winter range includes most of the continental United States as well as Mexico and Central America. Year-round populations can be found in the Aleutian Islands and the northern coast of Venezuela.
Vocalizations:
Lesser scaups are generally silent, but the females do use a raspy, barking or rippling “garf-garf-garf” call and males will use a faint, high-pitched whistle during the mating season.
Behavior
The lesser scaup is an accomplished diving duck and excellent swimmer, often swimming great distances underwater to emerge in a completely different area from where it dove. These ducks often congregate in mixed flocks with other types of ducks on suitable bodies of water, particularly in the winter.
Reproduction:
These are monogamous birds, and a mated pair will produce one brood of 5-15 eggs each breeding season. The female parent incubates the eggs for 22-28 days, and after the precocial chicks hatch they are ready to leave the nest that same day to forage, but they are too buoyant to dive for great lengths of time. The female continues to care for the young birds for 45-50 days until their first flight.
Attracting Lesser Scaups:
These are not backyard birds but they are common during the winter in urban and suburban parks where large ponds, rivers or marshes exist. Birders should not feed the ducks bread to attract them, however, as it can contaminate waterways and is poor nutrition for the birds. When birding in parks, dogs should be kept on a leash and children cautioned to not disturb the birds.
Similar Birds:
- Greater Scaup (Aythya marila)
- Ring-Necked Duck (Aythya collaris)
- Tufted Duck (Aythya fuligula)
Photo – Lesser Scaup – Male © Steve
Photo – Lesser Scaup – Female © Mike Baird, flickr.bairdphotos.com
