156Wildlife Conservation Plan for Seabirds

156 Wildlife Conservation Plan for Seabirds

White-bellied Sea-eagle (Haliaeetus leucogaster)

TABLE Species information for the White-bellied Sea-eagle (Haliaeetus leucogaster)

The White-bellied Sea-Eagle (Haliaeetus leucogaster) is a large raptor that has long, broad wings and a short, wedge-shaped tail. Females weigh between 2.8 and 4.2 kg, and are larger than the males, which weigh between 2.5 and 3.7 kg (Marchant and 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 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 and Emison 1983; Blakers et al. 1984; Marchant and 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 White-bellied Sea-Eagle breeds in solitary and monogamous pairs that mate for life. However, if one member of the pair dies, it is quickly replaced (Marchant and Higgins 1993). The breeding season extends from June to January (or sometimes February) in southern Australia, but begins one or two months earlier in northern Australia, for example, eggs are laid from June to September (or sometimes later) in southern Australia, and from May to August in northern Australia (Bilney & Emison 1983; Marchant and Higgins 1993). The nest is a large structure composed of sticks and lined with leaves, grass or seaweed (Marchant and Higgins 1993). Nests may be built in a variety of sites including tall trees (especially Eucalyptus species), bushes, mangroves, cliffs, rocky outcrops, caves, crevices, on the ground or even on artificial structures (Abbott 1982; Bilney and Emison 1983; Cupper and Cupper 1981; Emison and Bilney 1982; Marchant and Higgins 1993). Pairs usually return to the same breeding territory each year, and often the same nest, although territories tend to contain one or two additional, less developed nests (Marchant and Higgins 1993). Breeding pairs tend to be widely dispersed and are generally separated by distances of several kilometres or more (Marchant and Higgins 1993), though on offshore islands pairs may be located quite close together. The White-bellied Sea-Eagle feeds opportunistically on a variety of fish, birds, reptiles, mammals and crustaceans, and on carrion and offal (del Hoyo et al. 1994; Ferguson-Lees and Christie 2001; Marchant and Higgins 1993; Rose 2001).