When he first described the king eider in 1758, in the 10th edition of his opus Systema Naturae, Carl Linnaeus assigned it to the genusAnas, along with the rest of the ducks. In 1819, William Elford Leach moved it and the other large eiders to the genus Somateria, where it has remained since. It is very closely related to the other members of its genus, and is known to hybridise with the common eider. Despite its very large range, it is monotypic. The genus nameSomateria is a combination of the Greek words sōma, meaning "body", and erion, meaning "wool"; the combination is a reference to the eider's famously thick, soft down. The specific namespectabilis is Latin for "showy", "remarkable" or "worth seeing", a reference to the handsomeness of the adult male's plumage. The bird's common name, king eider, is a direct translation of its Icelandic name. It is called "king" because of the orange, crown-like knob above the male's bill; the male's multicoloured plumage also suggests royal robes. "Eider" is a Dutch, German or Swedish word derived from the Icelandic word æður, itself derived from the Old Norseæthr.
Description
The king eider is a large sea duck, measuring in length with a wingspan of. Males are, on average, heavier than females, with a mean weight of for males and for females. An individual bird's mass can vary considerably from season to season—from as little as to as much as. Like all eiders, the species is sexually dimorphic; the male is slightly larger and, in breeding plumage, much more colourful than the female. The male is unmistakable with its mostly black body, buff-tinged white breast and multicoloured head. The head, nape and neck are a pale bluish grey. The cheek is pale green. The bill, separated from the face by a thin black line, is red with a white nail and a large, distinctive yellow knob. Some tertials are curved up and form "spurs" along the back. The female is a warm brown colour overall, slightly paler on the head and neck. The feathers on her upperparts and flanks are marked with blackish, while those on her neck and head bear fine black streaks. She has a buffy spot at the base of her bill and a buffy eye ring which extends into a downward curving stripe behind her eye. Her bill is variously described as black or grey, and her legs and feet are greenish grey. Juvenile birds are greyish brown. Late in their first autumn, young males moult into a darker plumage, with white on the breast and rump; it takes them three years to achieve full adult plumage.
Habitat and range
The king eider is, found throughout the Arctic. It breeds on the Arctic coast of Alaska, Canada, Greenland, Svalbard and Russia, using a variety of tundra habitats. It winters in arctic and subarctic marine areas, most notably in the Bering Sea, the west coast of Greenland, eastern Canada and northern Norway. Wintering birds can form large flocks on suitable coastal waters, with some flocks exceeding 100,000 birds. It also occurs annually off the northeastern United States, Scotland and Kamchatka.
Behaviour
Food and feeding
The king eider's foraging strategies change depending on the season. For much of the year, it is at sea; there, it dives for benthic invertebrates. 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. It feeds on mollusks, crustaceans like king crabs, and on sea urchins, starfish and sea anemones.
Breeding
The female builds a scrape nest on the ground, usually near water. She lines it with vegetation and down feathers from her own body. She lays a clutch of, which she alone incubates for 22 to. The young are raised collectively by the females.
Voice
The male's song is a quavering, dove-like cooing, transcribed as croo-croo-croo or hoo-hoo-hooo. The female makes a variety of low clucks, grunts and growls.
Longevity
The oldest known king eider was a female that lived at least 18 years 11 months. She was ringed as an adult south of Gambell, Alaska in 1940, and shot in 1958 in Utqiagvik, Alaska.
The king eider, or qengallek in Yup'ik, is a regular source of fresh meat in the spring. They begin their migration past the Yukon-Kuskokwim Delta in late April and are hunted in great numbers. In May, several hundred thousand king eiders pass Point Barrow in northern Alaska on their way to Alaskan and Canadian breeding grounds.
