Haliaeetus leucogaster

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(White-bellied Sea Eagle)

FAMILY

Accipitridae:Falconiformes:Aves:Chordata:Animalia

Species

Haliaeetus leucogaster

Common name(s)

White-bellied Sea eagle, White-breasted Fish Hawk, White-breasted Sea Eagle

Main colour(s)

Adults: White and grey

Juveniles: dark brown with creamy markings

Size

75-85cm in length

180 – 220cm wingspan

Campus

Orpheus Island Research Station

Description

The White-bellied Sea-Eagle is a large raptor that has long, broad wings and a short, wedge-shaped tail. It measures 75–85 cm in length, and has a wingspan of 180–220 cm. Females weigh between 2.8 and 4.2 kg, and are larger than the males, which weigh between 2.5 and 3.7 kg (Clunie 1994; Marchant & Higgins 1993).

The plumage of adult birds is predominantly white and grey. The head, breast and belly, and the feathering on the legs, are white. The back and upper surfaces of the wings are grey, although the wings have black tips. The undersides of the wings are greyish-black around the distal edges, with a smaller area of white along the leading edge. The tail is grey at the base, and has a white tip. The bill is bluish-grey with a blackish tip, the iris is dark brown, and the legs and feet are a cream colour (Clunie 1994; Marchant & Higgins 1993). The juveniles differ from the adults in appearance in having predominantly dark brown plumage on the upper parts, except for the creamy colouring on the head, and creamy markings over the rest of the upper parts. The underside of the body is a similar colour to the upper parts, but becomes paler with wear. The under side of the wing is patterned with a mixture of orange-buff, white, dark brown and dark grey. There is a gradual transition from the brown and cream plumage of juvenile birds to the white and grey plumage of the adults. This transition is completed across a series of moults, over a period of several years (Clunie 1994; Marchant & Higgins 1993).

The White-bellied Sea-Eagle is generally seen singly or in pairs, though it may occasionally congregate around sites where food is abundant (Marchant & Higgins 1993). The White-bellied Sea-Eagle is distributed along the coastline (including offshore islands) of mainland Australia and Tasmania. It also extends inland along some of the larger waterways, especially in eastern Australia. The inland limits of the species are most restricted in south-central and south-western Australia, where it is confined to a narrow band along the coast (Barrett et al. 2003; Bilney & Emison 1983; Blakers et al. 1984; Marchant & Higgins 1993). Recent analysis indicates that the distribution of the sea-eagle may shift in response to climatic conditions, with an apparent decreased occupancy of inland sites (and increased occupancy of coastal sites) during drought conditions (Shephard et al. 2005a).

The total population size of the White-bellied Sea-Eagle is thought to be declining and it is listed under Appendix II of the CITES endanged species list. The main threats to the White-bellied Sea-Eagle are the loss of habitat due to land development, and the disturbance of nesting pairs by human activity (Bilney & Emison 1983; Clunie 1994; Dennis & Lashmar 1996; Mooney & Brothers 1986). The White-bellied Sea-Eagle is sensitive to disturbance when nesting, especially during the early stages of the breeding season, and may desert nests and young if confronted by humans or exposed to human activity (Clunie 1994; Hollands 2003; Mooney & Brothers 1986; Stokes 1996). Other potential threats to the White-bellied Sea-Eagle include poisoning, shooting, competition with Wedge-tailed Eagles, and the deterioration of inland water resources.

Sites where this species can be found at OIRS

White bellied sea eagles can be frequently seen throughout the Palm Island group with 1-2 breeding pairs found in the Pioneer Bay area. In 2010 both pairs successfully bred young.

Research that has been undertaken at OIRS

None

Haliaeetus leucogaster ( White-belied sea eagle) in flight.jpg