|Population||1,500,000 (2015 est)|
|Conservation status||Least concern|
The Arctic or black-throated loon (Gavia arctica) is a species of bird of the genus Gavia, found primarily in northern Eurasia, and the most common species of loon.
The Arctic loon is medium-sized, with a length of 23 to 29 inches, a wingspan of 39 to 51 inches, and weighs 2.9 to 7.5 pounds; females are slightly smaller than males. The iris of the eyes in young birds is brown, in adults it is dark red. Coloration, as in other loons, is primarily two-tone: a dark top over a white bottom.
At the male and female in the breeding plumage the head and neck are ashen-gray, the forehead is noticeably darker, the throat and the front part of the neck are black with a purple or greenish metallic tint (the subspecies viridigularis has a less-obvious purple tinting). In the lower part of the throat there is a transverse section with a longitudinal white pattern. The lateral parts of the neck are white with a longitudinal black line pattern that passes to the sides of the chest. The upper surface of the body is brilliantly black, brownish to the sides. In the anterior part of the back and in the humeral region rows of white quadrangular spots forming a chess pattern are seen, small round white spots are closer to the tail part. The underside is white. The lower part of the wing is white with an irregular dark pattern. Flight and tail feathers are brownish-black.
In the non-breeding adults, the female and the male have the upper and lower sides of the neck dark gray, the back and shoulder area dark brown, sometimes with small white spots. The front side of the neck, sides of the head, chest and belly are white. The border of the dark field on the head and neck is blurred, on the throat there are brownish spots. The plumage of chicks is similar to non-breeding adults, but of a slightly-darker brown shade.
- Gavia arctica arctica; Eurasia: western Palearctic east to Siberia (Lena River); winters to northwestern and southern Europe
- Gavia arctica viridigularis; northeastern Siberia to extreme western mainland Alaska, south to Manchuria; winters from the Kuril Islands to coastal Yellow Sea