Document ID: chunk:federal_register_of_legislation:F2022L00775:reg:18:p42
Version: federal_register_of_legislation:F2022L00775
Segment Type: reg
Provision Reference: reg 18 (pt 42/152)
Character Range: 156447–159611

Total estimates for North West Island, Heron Island Mast Head and Lady Musgrave in across the 1996-2000 period was 528,909 pairs. Populations of Wedge-tailed Shearwater had declined to 338,836 pairs by 2012–2015 survey period (Hemson 2015). There is no indication that the Capricorn Cays Wedge-tailed Shearwater population has begun to recover. The global population is suspected to be in decreasing but no trend data are available.

72 Wildlife Conservation Plan for Seabirds

Species profiles

 Conservation Concerns and Actions
Competition with commercial fisheries potential poses a threat to the species. Over-exploitation of tuna stocks is reducing prey availability (Brooke 2004) as the shearwaters rely on tuna to herd shoals of small fish to the surface where they become available for surface-feeding (Ratcliffe 1999). Human disturbance by visitors to islands where the species breeds have been found to negatively affect breeding success (Benoit and Bretagnolle 2002). Brown Rats (Rattus norvegicus) have in some cases caused local extirpations. Following the eradication of rats from several islands, the species has returned, and is again successfully breeding in these areas (Smith et al. 2006). Small amounts of plastic have been found in Wedge-tailed Shearwater chicks (Verlis et al. 2013). Increased sea surface temperatures have been demonstrated to reduce the provisioning rate, and above a particular temperature threshold reproductive success is nil (Chambers et al. 2011).

 Recommended Management Actions
    Investigate the locations and characteristics of key feeding sites during breeding and the means to retain their value under climate change

       Manage key sites to retain their value under projected climate change scenarios

       Regularly monitor breeding populations at index locations

       Determine non-breeding areas and migration routes

       Quantify impacts of fisheries interactions and human disturbance

Wildlife Conservation Plan for Seabirds 73
 Species profiles

 Buller's Shearwater (Ardenna bulleri)

  Life History and Distribution
Buller's Shearwater (Ardenna bulleri) is a large, lightly built shearwater closely resembling Wedge-tailed Shearwater (A. pacifica) in size and shape. The species is widespread in the subtropical south west Pacific Ocean and migrates in the non-breeding season to the northern Pacific Ocean, from Japan to North America. The main non-breeding moult zone appears to be the Emperor Seamounts, a chain of underwater volcanos northwest of Hawaii (BirdLife International 2019). The species occupies a range of marine habitats from inshore to shelf-edge and oceanic zones. The species is a breeding endemic to New Zealand, occupying a variety of habitats on the Poor Knights Islands (Aorangi and Tawhiti Rahi). It nests in burrows or on rock-crevices and ledges, often under dense vegetation. It feeds on krill, small fish, salps and jellyfish (Marchant and Higgins 1990, Heather and Robertson 1997).

  Population Estimates and Trends
The total population has been estimated at 2.5 million birds (Marchant