Thursday, March 1, 2007

White-bellied Sea Eagle

The White-bellied Sea-eagle (Haliaeetus leucogaster) and also known as the White-bellied Fish-eagle or White-breasted Sea Eagle, is a large bird of prey in the family Accipitridae which also includes many other diurnal raptors such as kites, buzzards and harriers.

It is resident from India through southeast Asia to Australia on coasts and major waterways. This large eagle is very distinctive. The adult has white head, breast underwing coverts and tail. The upperparts are grey and the black underwing flight feathers contrast with the white coverts. The tail is short and wedge-shaped as in all Haliaeetus species.

Its closest relative is the little-known Sanford's Fish-eagle of the Solomon Islands. These form a species pair, and as usual in sea eagle species pairs, as opposed to the dark-headed Sanford's, the White-bellied Sea-eagle has a white head. Talons, bill, and eyes are dark as in all Gondwanan sea eagles. This species pair has at every age at least some dark colouration in its tail, though this may not always be clearly visible in this species. Although they differ much in appearance and ecology, their ancestors diverged less than one million years ago

Description

The White-bellied Sea-Eagle is the second largest bird of prey found in Australia. The largest is the Wedge-tailed Eagle, Aquila audax, which stands up to 1m. The Wedge-tailed Eagle is mostly brown, with a wedge-shaped tail.

The Sea Eagle is white on the head, rump and underparts and dark grey on the back and wings. In flight the black flight feathers on the wings are easily seen when the bird is viewed from below. The large, hooked bill is grey with a darker tip, and the eye is dark brown. The legs and feet are cream-white, with long black talons (claws). The sexes are similar. Males (around 75cm in height) are slightly smaller than females (up to 85cm). The wingspan is about 2m.

Young Sea-Eagles are brown as juveniles then gradually come to resemble adults, acquiring the complete adult plumage by their fourth year.

Distribution and habitat

White-bellied Sea-Eagles are a common sight in coastal and near coastal areas of Australia. Birds form permanent pairs that inhabit territories throughout the year. Their loud "goose-like" honking call is a familiar sound, particularly during the breeding season. Birds are normally seen, perched high in a tree, or soaring over waterways and adjacent land.

In addition to Australia, the species is found in New Guinea, Indonesia, China, south-east Asia and India.

Food and feeding

The White-bellied Sea-Eagle feeds mainly off aquatic animals, such as fish, turtles and sea snakes, but it takes birds and mammals as well. It is a skilled hunter, and will attack prey up to the size of a swan. Sea-Eagles also feed on carrion such as sheep and fish along the waterline. They harass smaller birds, forcing them to drop any food that they are carrying. Sea-Eagles feed alone, in pairs or in family groups.

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