This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern (IUCN, 2009).
The King Eider breeds along the northern hemisphere Arctic coasts of Europe, North America and Asia. It can be found further south during the winter, including the north-east and north-west coast of North America, on Iceland and islands north of the United Kingdom, and on the Pacific coast of Asia to the tip of the Kamchatka Peninsula (Russia) (del Hoyo et al. 1992).
The global population is estimated to number c.790,000-930,000 individuals (Wetlands International 2006), while the population in Russia has been estimated at c.10,000-100,000 breeding pairs and c.1,000-10,000 wintering individuals (Brazil 2009).
Above: adult male King eider in breeding plumage
Above: a pair of adult King eiders in breeding plumage
Above: adult female King eider in breeding plumage
Above: adult male King eider in breeding plumage
Above: adult male King eider in breeding plumage
Adult: adult male in eclipse plumage
Above: female king eider
Above: King eider, adult female