Lesser Scaup


	Lesser Scaup
	Aythya affinis

Two scaup species live in North America: the Greater Scaup prefers salt water and is found in America and Eurasia, while the Lesser Scaup prefers freshwater and is found only in North America. The Lesser Scaup is one of the most abundant and widespread of the diving ducks in North America

Interesting Information

The Lesser Scaup is a regular, if relatively uncommon, visitor to Hawaii, and is the third most abundant duck in the state. Only the Hawaiian Duck actually breeds there.
An adult Lesser Scaup may pretend to be dead (immobile with head extended, eyes open, and wings held close to body) when grasped by a red fox.
Lesser Scaup chicks are capable of diving under water on their hatching day, but they are too buoyant to stay under for more than just a moment. By the time they are 5 to 7 weeks old they are able to dive for 2-25 seconds and swim underwater for 15-18 meters (50-60 ft).

Description

Adult Description

Size: 39-46 cm (15-18 in)
Wingspan: 68-78 cm (27-31 in)
Weight: 454-1089 g (16.03-38.44 ounces)
Medium-sized diving duck.
Slight bump or peak on back of head.
Bill bluish with small black tip.
Male with black head, chest, and rear end, and gray sides (black on the ends and white in the middle).
White stripe extends only half-way out wings.
Eyes yellow.
Legs grayish, with dark gray webs.

Sex Differences

Breeding male bold black-and-white; female drabber and more brown with white patch at base of bill.

Male

Breeding (Alternate) Plumage

Head, neck, upper back, and breast black; head with purplish iridescence. Back white, covered with thin, black wavy lines. Rump black. Belly white. Sides white, with some fine dark streaks. Undertail black.

Nonbreeding (Basic) Plumage

Similar to female, but with only a few white feathers on face instead of a large white patch. Head and neck blackish brown. Breast dark with some white edging to feathers. Back brown with white edges to feathers. Underparts mottled brownish and white. Tail dark grayish.

Female

White area at base of bill. Head and neck dark brown with some light mottling. Back darkish brown with white flecks. Breast buffy brown. Belly whitish. Sides and flanks brown. Tail dark brown.

Immature

Similar to adult female.

Photo taken from: The Sibley Field Guide by David Allen Sibley

Habitat

Found on lakes and ponds. Winters in fresh or brackish water.

Behavior

Dives under water to capture food.

Food

Clams, snails, crustaceans, aquatic insects, seeds, and aquatic plants.

Taxonomy

Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Vertebrata
Class:	Aves
Order:	Anseriformes
Family:	Anatidae
Subfamily:	Anatinae
Genus:	Aythya
Species:	Aythya affinis

Similar Species

Greater Scaup extremely similar, but is slightly larger, has a smoothly rounded head, a large black nail on the bill tip, and has a white stripe extending farther than halfway out the wing. Male Greater Scaup shows greenish sheen on head and usually brighter white sides.
Male Ring-necked Duck has black back, white shoulder, and a more pronounced bump on the back of the head. Female shows ring around her eyes and a white spot on the bill.

Bird Sound

Male makes faint whistled "whe-o" in courtship. Female makes grating "garf, garf."

Eggs look like this

Photo taken from: ARCTOS Collaborative Collection Management Solution

Videos

Lesser Scaup 1

Male and Female

Lesser Scaup 2

Male - Just Chill'n

	Sources Used To Construct This Page
	Austin, J. E., C. M. Custer, and A. D. Afton. 1998. Lesser Scaup (Aythya affinis). In The Birds of North America, No. 338 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

	All photos and videos © Rick Swartzentrover - Free for non-profit use.