Cold temperate to polar latitudes of the northern hemisphere
Nest on tundra; feed in freshwater and coastal waters
Order Anseriformes (water fowl), Family Anatidae (ducks, geese, and relatives)
The king eider is a sea duck that lives in the Arctic Ocean and adjacent waters. It gets its common name from the intricate color patterns on its head, which resemble a crown. Interestingly, though it is the “king,” this duck is smaller than its closest relative, the common eider (Somateria mollissima). Like most ducks and relatives, the king eider is migratory, flying south during the colder months and north during summer months.
King eiders eat a variety of invertebrate prey, diving for benthic mollusks and crustaceans. They also often enter fresh or brackish water to feed on insect larvae (especially caddisflies and midges), and they are known to eat some plant material when nesting.
Though the king eider is predominately marine, it nests inland on dry Arctic tundra. After returning from wintering grounds in southern fjords, these birds form relatively isolated breeding pairs. They reproduce via internal fertilization, and females lay fertilized eggs into nests directly on the tundra surface. Both males and females incubate the eggs and care for the chicks. When the king eider is not breeding, it spends much of its time associated with the ice edge. Though they isolate themselves during breeding, king eiders are quite social the rest of the year and can be observed in flocks of at least a thousand individuals.
The king eider is a common species throughout most of its range, but scientists believe the populations to be decreasing, likely a result of oil pollution, legal hunting, and other human threats. Populations are still high enough for scientists to consider this species one of least concern, but with continuing expansion of oil and gas exploration in the Arctic Ocean and adjacent seas, king eider populations may become more at risk of endangerment.