Document ID: chunk:federal_register_of_legislation:F2022L00775:reg:18:p34
Version: federal_register_of_legislation:F2022L00775
Segment Type: reg
Provision Reference: reg 18 (pt 34/152)
Character Range: 134504–137513

breeding islands. Ingestion of marine debris may impact some individuals.

Recommended Management Actions
        Gain an improved understanding of the at sea distribution in the Southern Ocean

        Quantify the breeding population on Heard Island

        Work with range states to 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 63
 Species profiles

 Broad-billed Prion (Pachyptila vittata)

  Life History and Distribution
  The Broad-billed Prion (Pachyptila vittata) is the largest prion with a large, broad, glossy iron grey bill, high forehead, sombre facial pattern and prominent blue-grey collar impart appearance of large dark head compared to other prions. The species has an extremely large range extending from the Southern Ocean to the South Atlantic Ocean. The species breeds on Gough Island and Tristan da Cunha in the south Atlantic Ocean and on the Chatham Islands, New Zealand. Breeding starts in July or August and individuals are strongly colonial, nesting in burrows which are sometimes occupied by more than one pair. Broad-billed Prions breed on a variety of substrates and areas including, coastal slopes, flat lava fields, offshore islets and cliffs, dry rocky soil, caves and scree. Adults are thought to remain in waters adjacent to breeding colonies, however, young birds seem to occur farther north to Australia and South Africa. The diet of this species is comprised mostly of crustaceans (especially copepods), squid and some fish. The species apparently takes more crustaceans in summer and small squid in winter. Prey is obtained usually by hydroplaning and by filtering or surface seizing.

  Population Estimates and Trends
The global population has been estimated to exceed 15 million individuals (Brooke 2004). The population is suspected to be decreasing owing to predation from invasive species.

  Conservation Concerns and Actions
  The main threats faced by the Broad-billed Prion come from introduced
predators. House Mice (Mus musculus) on Gough Island are adversely impacting reproductive success and causing very rapid population decreases (Cuthbert et al. 2013, Dilley et al. 2015). Estimates of breeding success were only 6 per cent from the 2009-10 and 2010-11 breeding seasons (Cuthbert et al. 2013), and chick mortality in 2014 was 100 per cent (Dilley et al. 2015). The population by 2000-01 had already been estimated to have reduced by more than 80 per cent since the 1960s (Carboneras et al. 2018). In New Zealand, rapid decreases and local extirpations have occurred following the introduction of other invasive predators to breeding islands, including rats and stoats in Dusky Sound, Fiordland, cats (Felis catus) on Herekopare Island and Weka (Gallirallus australis) on Jacky Lee Island (Miskelly 2013). Severe weather events