154Wildlife Conservation Plan for Seabirds

154 Wildlife Conservation Plan for Seabirds

Osprey (Pandion haliaetus)

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TABLE Species information for the Osprey (Pandion haliaetus)

The Osprey (Pandion haliaetus, also known as Pandion cristatus) is a familiar coastal raptor, particularly in northern Australia. Ospreys occur in littoral and coastal habitats and terrestrial wetlands of tropical and temperate Australia and offshore islands. They are mostly found in coastal areas but occasionally travel inland along major rivers, particularly in northern Australia (Johnstone & Storr 1998; Marchant & Higgins 1993; Olsen 1995). They require extensive areas of open fresh, brackish or saline water for foraging (Marchant and Higgins 1993). They frequent a variety of wetland habitats including inshore waters, reefs, bays, coastal cliffs, beaches, estuaries, mangrove swamps, broad rivers, reservoirs and large lakes and waterholes (Marchant and Higgins 1993). They exhibit a preference for coastal cliffs and elevated islands in some parts of their range (Boekel 1976; Domm 1977), but may also occur on low sandy, muddy or rocky shores and over coral cays (Marchant and Higgins 1993). The Osprey breeds from April to February in Australia. Breeding seasons of individual pairs vary according to latitude, with breeding commencing progressively later on a cline from north to south (Marchant and Higgins 1933). Ospreys mainly feed on fish, especially mullet where available.

The global population size of the Osprey is not precisely known but is estimated to number less than 212,000 pairs (Ferguson-Lees and Christie 2001; Poole et al. 1989; Rich et al. 2004). Global trends have not been quantified. The Osprey is considered to be moderately common in Australia (Olsen 1998). The species is most abundant in northern Australia, where high population densities occur in remote areas (Garnett 1993; Johnstone and Storr 1998). The species is rare to uncommon in southern Western Australia (Johnstone and Storr 1998) and occurs in low numbers in South Australia (~52 pairs in 2005, Dennis 2007), and NSW (~100 pairs in 1996, Clancy 2006).

The main threat to the Osprey in Australia is loss, degradation or alteration of habitat for urban or tourism development in coastal areas (Clancy 1989, 1991; Dennis 2007a; Olsen 1998). In the Chain of Bays region of the Eyre Peninsula, South Australia, where Ospreys nest on the ground due to the lack of trees, human disturbance is an increasing threat (Department of the Environment 2019b).

Other less pervasive threats include ingestion of prey items containing pollutants such as pesticides, heavy metals or fishing tackle; competition for food with commercial and recreational fisheries; reduced water quality at foraging grounds caused by discharge of effluent or runoff; disturbance or persecution by humans; and accidental mortality arising from collisions with powerlines (Department of the Environment 2019b).