From Opus

Haliaeetus pelagicus

Photo by stoop
Location: Shiretoko, Hokkaido, Japan

[edit] Identification

Largest member of the genus Haliaeetus. Weighing from around 5 kilograms for compact yet robust males (88cm length and 220cm wingspan), to huge 9 kilogram females, 103cm in length and a wingspan of 245cm. Adults appear dark umber brown to almost black with white shoulders and white tail with huge, bright yellow bill and feet. In flight leading wing edges are white and white tail is obviously wedged.

Trailing wing edges are rounded identifying immature or young birds from young White-tailed Sea Eagles (Haliaeetus albiicilla), which has straighter trailing wing edges, shorter tail, and smaller bill.

[edit] Distribution

North-east Asia: breeds on the Pacific coast of north-east Asia and northern parts of the Korean peninsula, wintering mainly in Korea and Japan, particularly on the Shiretoko Peninsula of Hokkaido. Rarely wanders to China and a vagrant to Pribilof and Aleutian Islands. In the Western Palearctic recorded in Germany in March 1991 and presumably the same bird in Finland in April-August of the same year and again in May 1992. In May 1993 another or the same was reported from Sweden and again in June-July in Finland. In September 1993 a Steller's Sea Eagle, presumably the same, was found dead in Estonia. This is a rather unlikely vagrant to Europe and all reports are generally thought to involve a single escaped bird. However, the species is rare in captivity and no losses were reported.

[edit] Taxonomy

This is a monotypic species¹.

A darker form with white tail but lacking white shoulders which occurs with extreme rarity is sometimes regarded as a subspecies, niger but is probably better regarded as a colour morph².

[edit] Habitat

Breeds on sea-cliffs or in tall trees, winters on coasts or on rivers where salmon come to spawn. Often gathers in some numbers on gravel banks in rivers or on ice-floes.

[edit] Behaviour

The diet includes fish, especially salmon and trout, water-dwelling birds, mammals and carrion.

It builds several aeries high up on trees and rock. The first white-green egg is laid and incubated for 39 - 45 days. At about ten weeks, the young birds learn to fly. They reach sexual maturity at 4-5 years. Full adult plumage in the Steller's Sea Eagle appears at 8-10 years.

[edit] References

1. Clements, JF. 2009. The Clements Checklist of Birds of the World. 6th ed., with updates to December 2009. Ithaca: Cornell Univ. Press. ISBN 978-0801445019.
2. Birdforum thread discussing a dark morph Steller's Sea Eagle.

[edit] External Links

• View more images of this species on Orientalbirdimages