114Wildlife Conservation Plan for Seabirds

114 Wildlife Conservation Plan for Seabirds

 Determine the subspecies status breeding within the Ashmore Reef Marine Park

 Investigate the location and characteristic of key feeding sites and the means to retain their value under climate change

 Implement best practice quarantine measures at breeding colonies to reduce the risk of any invasive species (re)establishing on islands

Photograph of closeup view of the seabird Masked Booby

Wildlife Conservation Plan for Seabirds 115

Red-footed Booby (Sula sula)

TABLE Species information for the Red-footed Booby (Sula sula)

The Red-footed Booby (Sula sula) is the smallest and lightest booby with a typical sulid silhouette in flight. This species is found in tropical islands in most oceans, excluding the eastern Atlantic. It winters at sea in the same area, ranging north of the Tropic of Cancer and south of the Tropic of Capricorn (del Hoyo et al. 1992). This species is largely pelagic occurring farther from land than other booby species. It feeds mainly on flying-fish and squid. Prey is caught by plunge-diving, but flying fish are also taken in flight, especially when chased by underwater predators. It often rests on boats using them as vantage points. Breeding is not seasonal in most of its range and egg and chicks have been recorded in all months. Individuals form large colonies, nesting and roosting mainly in trees or on islets with abundant vegetation (del Hoyo et al. 1992).

The global population is estimated to number >1,000,000 individuals (del Hoyo et al. 1992). Globally, the population is suspected to be decreasing owing to habitat loss, predation by invasive species and unsustainable levels of exploitation. Indonesian populations are under threat from human activity, including hunting and habitat loss, and the Red-footed Booby has long been extinct as a breeding species in western Indonesia (de Korte and Silvius 1994; de Jong 2011). The most important breeding population in Australia occurs in Pulu Keeling National Park which regularly supports more than 30,000 pairs. Christmas Island has an estimated 12,000 pairs and the species is also present on the islands of Ashmore Reef Marine Park (248 pairs). Several colonies occur on islands and cays in the Great Barrier Reef and Coral Sea Marine Park. Baker and Holdsworth (2013) reported that from a regional perspective, the Herald Cays (Coral Sea Marine Park) contain a significant proportion of the region’s breeding population of Red-footed Booby. As of 2012, there were 20-year and 10-year data sets available for North East Cay (Herald Cays) and South West Cay (Herald Cays), respectively and the Red-footed Booby population increased by an annual rate of 3.8 per cent. The total Australian population and trends are unknown.