Document ID: chunk:federal_register_of_legislation:F2022L00775:reg:18:p97
Version: federal_register_of_legislation:F2022L00775
Segment Type: reg
Provision Reference: reg 18 (pt 97/152)
Character Range: 307296–310326

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 at sea (Haney et al. 1999). Migratory movements have been documented from Houtman Abrolhos to the Celebes Sea, 3,800 km north (Surman et al. 2018) and some populations in the Indian Ocean seem entirely sedentary or only partially migratory (Haney et al. 1999). The timing of breeding varies geographically, most populations breeding annually in suitable habitat (Haney et al. 1999).

Population Estimates and Trends
The global population is estimated to number between 610,000–1,500,000 individuals (Delany and Scott 2006). The overall population trend is uncertain, as some populations are decreasing, while others are increasing or have unknown trends (Delany and Scott 2006). The species is common in WA (22,000–48,121 pairs; Burbidge et al. 1996) and Queensland (King 1996). The species is known to breed on islands of Ashmore Reef Marine Park. In 2019, surveys reported 400 adults across islands and cays of Ashmore Reef Marine Park (Cannell and Surman 2020).

Species profiles

Conservation Concerns and Actions
The Bridled Tern is known to have abandoned breeding colonies when subject to high levels of human disturbance, although at sites exposed to long-term visitation it may become habituated to continuous and predictable human presence and activity (Haney et al. 1999). Measures to reduce human disturbance of nesting colonies include the erection of barriers and signs, the provision of walkways, and the supervision and education of visitors (Haney et al. 1999). Eggs are harvested for subsistence in the Bahamas and the West Indies, and eggs and chicks are harvested on some islands in the Pacific by local residents and coastal shipping crews (Haney et al. 1999). Neither of these are considered to represent a significant threat to the population but no assessment has been made. 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

        Determine non-breeding areas and migration routes

        Quantify and manage the potential impacts of human disturbance

        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

Wildlife Conservation Plan for Seabirds 133
Species profiles

Sooty Tern (Onychoprion fuscatus)

  Life History and Distribution
  The Sooty Tern (Onychoprion fuscatus) is a medium-sized tropical tern, slightly larger than Bridled Tern and larger than the noddies (Anous spp.). The species has an extremely