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White-Bellied Sea-Eagle (Haliaeetus Leucogaster)

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White-Bellied Sea-Eagle (Haliaeetus Leucogaster) #60 This Action Statement was first published in 1994 and remains current. This White-bellied Sea-eagle version has been prepared for web publication. It Haliaeetus leucogaster retains the original text of the action statement, although contact information, the distribution map and the illustration may have been updated. © The State of Victoria, Department of Sustainability and Environment, 2003 Published by the Department of Sustainability and Environment, Victoria. White-bellied Sea-eagle (Haliaeetus leucogaster) Distribution in Victoria (DSE 2002) 8 Nicholson Street, (Illustration by John Las Gourgues) East Melbourne, Victoria 3002 Australia Description and Distribution disperse widely (Favaloro 1944). If one of a The White-bellied Sea-Eagle, Haliaeetus pair dies, it is quickly replaced by a bird This publication may be of from the 'pool' of unpaired individuals (R. assistance to you but the leucogaster (Gmelin), is a large white bird of Chatto pers. comm.). One or two whitish- State of Victoria and its prey with broad greyish wings and a short employees do not guarantee pale wedge-shaped tail (length 75-85 cm, yellow eggs are produced usually between that the publication is wingspan 180-220 cm). Adults have a white April and August, although the timing of without flaw of any kind or head, breast and abdomen, and the tail is breeding appears to vary with latitude, is wholly appropriate for pale grey with a white tip. Juveniles are occurring later further from the equator your particular purposes speckled slaty brown with a paler face. By (Bilney & Emison 1983). Nests, which can be and therefore disclaims all the second year, they are whiter in colour used for years in succession, are constructed liability for any error, loss of sticks lined with leaves and can become or other consequence which although patchy. Females are larger than very large as new material is added (Bilney may arise from you relying males. Juveniles and immature birds may on any information in this sometimes be confused with Wedge-tailed & Chatto 1986). publication. Eagles (Aquila audax). The voice is Nests are usually near water, in tall live or distinctive: a 'loud deep goose-like honking dead trees or on remote coastal cliffs. River ISSN 1448-9902 or cackling; begging juveniles give more Red Gum (Eucalyptus camaldulensis), Forest prolonged yelping or wailing' (Marchant & Red Gum (E. tereticornis) and Southern Higgins 1993). Males have a slightly higher Mahogany (E. botryoides) are commonly pitched and quicker call (R. Chatto pers. used as nest trees (Emison & Bilney 1982). comm.). For a detailed discussion on On islands free of pre-dators, nests may be identification see Marchant & Higgins close to the ground in shrubs or rocky (1993). platforms (Marchant & Higgins 1993). Birds Birds form pairs for life and are mostly rarely use artificial structures as nest sites. sedentary once a home range has been White-bellied Sea-Eagles are generally seen established, although immature birds can alone or in pairs, although they sometimes congregate where food is abundant (Baker-Gabb 1987, especially on the central and western coasts. Habitat Lawrence pers. comm.). destruction represents the most significant threat to the species, They are opportunistic carnivores, feeding on birds, as it has resulted in the direct loss of nesting sites and has mammals, fish, reptiles and carrion (Green 1959, Quinn caused birds to nest in suboptimal habitat types where 1969, Smith 1985). Birds often have favoured roosts on breeding success can be reduced (Bilney & Emison 1983). prominent trees and soar in large circles with wings On the other hand, it is possible that the number inhabiting upswept during flight. While hunting they may hover low some inland areas has increased following European settlement and dive close to the water to catch prey. Pairs may hunt because of the stabilisation of water levels in major rivers by together and they are known to harass other bird species weirs, the construction of reservoirs and dams and the (such as terns) and either steal prey or have them associated increase in food supply as well as the introduction regurgitate it. of European Carp (Cyprinus carpio), a favoured food item White-bellied Sea-Eagles have been recorded in the (Bilney & Emison 1983). northern hemisphere from India to China and south Increased human presence has been detrimental to nesting through Asia, New Guinea and Australia. They occur along White-bellied Sea-Eagles because they are sensitive to the coastline of Australia and also range inland over large disturbance and may desert nests and young. Although there is rivers and wetlands (Bilney & Emison 1983, Blakers et al. little direct evidence, other possible threats which may be 1984). In Victoria they are most common between Gabo implicated in the decline in the species in Victoria include: Island and Wilsons Promontory; although there are one or • direct poisoning during Dog and Fox control two resident pairs in Western Port and birds are recorded programs; through to Port Phillip Bay and occasionally further west. • secondary poisoning during Rabbit control programs; Populations also exist along the Murray and Goulburn • deliberate shooting; Rivers and they are sometimes recorded over other inland • eggshell thinning because of the past use of DDT; and areas on impoundments where there are plenty of large • food chain contamination by heavy metals (Bilney & trees (Atlas of Victorian Wildlife). They favour forested Emison 1983). coasts and forested margins of inland waterways (Emison In its final recommendation the Scientific Advisory Committee et al. 1987). (1992a) has determined that the White-bellied Sea-Eagle is: The total Victorian population is thought to be extremely • in a demonstrable state of decline which is likely to low: possibly only 100 breeding pairs survive (R. Bilney result in extinction; pers. comm.). Distribution records indicate two population • significantly prone to future threats which are likely concentrations - approximately 25 pairs around the to result in extinction; and Gippsland Lakes and 25 pairs around Corner Inlet - and a • very rare in terms of abundance or distribution. further 50 pairs scattered throughout the rest of Victoria. Major Conservation Objective Conservation Status Immediate objectives are to: Current Status • obtain an accurate estimate of the total breeding CNR (1993) Rare population of White-bellied Sea-Eagles in Victoria SAC (1992) Threatened within five years; • identify and protect all known nest sites; The White-bellied Sea-Eagle has been listed as a threatened • maintain and improve areas of suitable habitat. taxon on Schedule 2 of the Flora and Fauna Guarantee Act The long-term objectives are to: 1988. • halt the decline in numbers of the White-bellied Sea- Eagle; Reasons for Conservation Status • ultimately increase the population size; and Although little is known of the sizes of territories of the • ensure that the Victorian population, in conjunction White-bellied Sea-Eagles, it appears that active nest sites are with adjacent populations, is genetically viable. quite widely spaced. The recorded distances between active nest sites have varied, being 4-13 km in the Gippsland Management Issues Lakes (25 breeding pairs in 400 km2), 10 km in Barmah Forest and 40-65 km along the Murray River (Bilney & Ecological Issues Specific to the Taxon Emison 1983, Fleay 1948, R. Bilney pers. comm., R. Lyon Few studies of the White-bellied Sea-Eagle in Victoria have pers. comm.). It is probable that the White-bellied Sea-Eagle been undertaken and little is known regarding its ecological has never occurred in high densities in Victoria. requirements. The White-bellied Sea-Eagle has not been well studied in The protection of nest sites is clearly a significant factor in the Victoria, but the Murray River population is known to be conservation of this species. They are found in a range of small and is considered vulnerable to pesticide habitat and tree types and are likely to be selected according to contamination due to its fish-eating habits (Robertson et al. food availability. Several nests of the same pair may exist 1989). Decline over much of its coastal range in Victoria within a territory, so a count of nests may not accurately could be presumed because of the widespread clearing of indicate population numbers. White-bellied Sea-Eagles coastal forests for agriculture and urban expansion, occasionally occupy disused nests of Whistling Kites (Haliastus 2 sphenurus) and Wedge-tailed Eagles (R. Chatto & I. linked to declines of the White-tailed Sea-Eagle (Haliaeetus Davidson pers. obs.). albicilla) in Sweden (Newton 1979). A study of breeding success of White-bellied Sea-Eagles in The use of lead shot in cartridges for hunting waterfowl is the Gippsland Lakes region indicated that the production of listed as a potentially threatening process under the Flora and young varied in relation to habitat type. Of the 13 nesting Fauna Guarantee Act 1988. The final recommendation report territories of White-bellied Sea-Eagles which were noted that the range of fauna possibly affected by the process surveyed, those in remnant patches of tall open forest included predatory species such as the White-bellied Sea-Eagle averaged 1.2 young per territory compared with 0.2 young (SAC 1992a). Raptors are affected by eating the liver or kidneys per territory for birds inhabiting pasture with isolated trees (where lead is concentrated) or from lead shot in the gizzard or (Bilney & Emison 1983). body of their prey. Bald Eagles have died from lead poisoning White-bellied Sea-Eagles are sensitive birds and may desert in the USA (Pattee et al. 1981). nests and young if disturbed by humans. Thus the The increase of sediment input into rivers and streams due to avoidance of nest sites by humans during the breeding human activities is listed under the Flora and Fauna Guarantee season is particularly important.
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