The birds spend most of the year in coastal marine ecosystems at high latitudes, and migrate to Arctic tundra to breed in June and July.

When he first described the king eider in 1758, in the 10th edition of his opus Systema Naturae, Carl Linnaeus assigned it to the genus Anas, along with the rest of the ducks.

The bill, separated from the face by a thin black line, is red with a white nail and a large, distinctive yellow knob.

[12] The female (occasionally colloquially referred to as a "queen eider")[13] is a warm brown colour overall, slightly paler on the head and neck.

The feathers on her upperparts and flanks are marked with blackish chevrons, while those on her neck and head bear fine black streaks.

[8] It winters in arctic and subarctic marine areas, most notably in the Bering Sea, the west coast of Greenland, eastern Canada and northern Norway.

During the breeding season, it does more of its foraging on freshwater lakes and ponds, where it dabbles, feeding primarily on small invertebrates plucked from the surface of the water.

[19] Due to its large population and vast range, the king eider is listed as a species of least concern by the International Union for Conservation of Nature.

As eggs and young, king eiders have many predators, including glaucous gull, common raven, parasitic jaeger and Arctic fox.

In May, several hundred thousand king eiders pass Point Barrow in northern Alaska on their way to Alaskan and Canadian breeding grounds.