Histrionicus histrionicus
SUBFAMILY
Merginae
TAXONOMY
Anas histrionicus Linnaeus, 1758, America = Newfoundland ex Edwards. Monotypic.
OTHER COMMON NAMES
English: Harlequin; French: Arlequin plongeur; German: Kragenente; Spanish: Pato Arlequín.
PHYSICAL CHARACTERISTICS
15.0–20.1 in (38–51 cm); 1.2–1.5 lb (540–680 g). Distinctive white markings on head, chest, and back.
DISTRIBUTION
Eastern Siberia from Lake Baikal north to about 68° and east to central western Alaska and Yukon. South in North America to California and east to southern Baffin Island and Quebec. Greenland, and Iceland. Winters along coasts of Kamchatka, Bearing Sea islands, Japan, Korea, China, California, and from southern Labrador south to Long Island.
HABITAT
Fast flowing rocky rivers during the breeding season and rocky coastlines during the nonbreeding season.
BEHAVIOR
Loosely territorial and aggressive. Males guard their mate. Return to the same breeding area each year. Migratory.
FEEDING ECOLOGY AND DIET
Has mostly an animal diet of invertebrates and some fish. Mostly dives for food, but also dabbles, up-ends, and dips its head in shallow water.
REPRODUCTIVE BIOLOGY
Seasonally monogamous until midincubation. Same birds may re-pair in the following season. Breeding begins May–Jun. The nest is well hidden on the ground. Commonly lays 5–7 eggs; incubation 27–29 days; fledging c. 60–70 days; becomes sexually mature at 2 years.
CONSERVATION STATUS
Not threatened. Locally common with stable populations.
SIGNIFICANCE TO HUMANS
None known.





