Document ID: chunk:federal_register_of_legislation:F2022L00775:reg:18:p96
Version: federal_register_of_legislation:F2022L00775
Segment Type: reg
Provision Reference: reg 18 (pt 96/152)
Character Range: 304616–307550

length 17 mm), squid, crustaceans and pelagic sea striders with proportions varying seasonally and geographically. It feeds on the wing by dipping or pattering.

Population Estimates and Trends
The combined populations of Anous ceruleus and A. albivittus are estimated to number 27,000–120,000 individuals, but the total for A. albivittus is unknown. The global population trend is stable, although some populations have unknown trends (Delany and Scott 2006). Australian population estimates and trends are unknown.

Conservation Concerns and Actions
Globally, the species is threatened by invasive species. Rodents on Lord Howe Island restrict breeding and rodent free islands have over 80 per cent breeding success (N. Carlile pers. comm). On Easter Island, the population is thought to be threatened by cat predation (Marin and Caceres 2010). It is possible that, in the future, the effects of climate change could have an adverse impact on food sources and breeding habitat.

Recommended Management Actions
        Quantify the breeding population in Australia

        Regularly monitor breeding populations at index locations

        Control, or eradicate invasive species on breeding islands

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

Species profiles

Bridled Tern (Onychoprion anaethetus)

Life History and Distribution
The Bridled Tern (Onychoprion anaethetus) is a medium-sized tropical tern, with a stout bill about the same length as head, long slender wings and a long deeply forked tail. The species is slightly smaller and slimmer than Sooty Tern (O. fuscata). The Bridled Tern breeds off the Pacific and Atlantic coast of Central America including the Caribbean, off small areas of western Africa, around Arabia and eastern Africa down to South Africa, off the coast of India, and in much of south-east Asia and Australasia excluding southern Australia and New Zealand (del Hoyo et al. 1996). It breeds on the periphery of vegetated coastal and continental (Haney et al. 1999) coral, rock or rubble islands and beaches (Higgins and Davies 1996, del Hoyo et al. 1996, Haney et al. 1999), volcanic stacks and exposed reefs (Haney et al. 1999). The nest is a scrape or depression in shingle or sand (Higgins and Davies 1996) that may be freshly excavated or re-used from a previous season (Higgins and Davies 1996). Nests are placed in a variety of concealed locations (Higgins and Davies 1996, del Hoyo et al. 1996). The species is not strictly colonial but solitary pairs usually congregate in suitable habitats (Haney et al. 1999) with neighbouring nests spaced according to nest-site availability (usually 1-5 m apart, minimum 30 cm) (del Hoyo et al. 1996). Most populations are migratory and dispersive and abandon their breeding sites at the end of the breeding season to overwinter