96Wildlife Conservation Plan for Seabirds

96 Wildlife Conservation Plan for Seabirds

Black-winged Petrel (Pterodroma nigripennis)

TABLE Species information for the Black-winged Petrel (Pterodroma nigripennis)

The Black-winged Petrel (Pterodroma nigripennis) is a small compact gadfly petrel with a grey and white plumage, almost complete grey collar. The Black-winged Petrel breeds in the south-west Pacific, in Lord Howe Island (Australia), New Caledonia, the Chatham Islands (New Zealand) and Austral Islands (French Polynesia). It breeds in colonies, usually making burrows on high ground inland amongst scrub or tussock grass (del Hoyo et al. 1992). Outside the breeding season it migrates to the north and east Pacific, being common in the north-west Pacific in July–November, and particularly abundant between the Hawaiian Islands (U.S.A.) and Peru. Little is known about its diet, but it is known to include cephalopods and prawns which it catches mainly by surface-seizing and dipping, but also pattering. It has often been recorded feeding in association with other shearwaters and petrels.

Brooke (2004) estimated the global population to number 8 –10 million individuals. In recent decades the species seems to have expanded westwards. Attempts to colonise Norfolk Island have been unsuccessful due to cat predation. On Lord Howe Island, the population is approximately 500–600 pairs and on Phillip Island, (Norfolk Island group) the population in 2017 was estimated at 15,000- 18,000 pairs (N. Carlile pers. comm). Australian trends are unknown but are thought to be increasing.

Cats predate Black-winged Petrels on Norfold Island (Priddel et al. 2010).

Polynesian Rats may be keeping populations low on islands where they are still present but have been eradicated from the islands where the vast majority of birds breed (Greene et al. 2014). Rabbits may have been a problem in the past on Phillip Island, Australia, but have since been eradicated and the population is increasing. Volcanoes represent a genuine threat to this species, with Macauley Island, containing 2-3 million breeding pairs, on the edge of an active submarine caldera and Curtis Island, containing 300,000 breeding pairs, is an active volcano.

 Quantify the breeding population on Lord Howe and Phillip Island

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

 Establish a Norfolk Island breeding colony

Wildlife Conservation Plan for Seabirds 97

Common Diving-petrel (Pelecanoides urinatrix)

TABLE Species information for the Common Diving-petrel (Pelecanoides urinatrix)

The Common Diving-petrel (Pelecanoides urinatrix) is a small stocky diving-petrel with a ‘neckless’ and short-tailed appearance resembling Northern Hemisphere auks (Alcidae). Very similar in appearance to South Georgian Diving-petrels (P. georgicus) and are largely indistinguishable at sea. The Common Diving-petrel has discrete ranges surrounding oceanic islands in the south Atlantic at South Georgia (Georgias del Sur), the Falkland Islands (Islas Malvinas), Tristan da Cunha and Gough Island (St Helena to UK), in the south Indian Ocean, south and east of New Zealand (e.g. Antipodes Islands), New Zealand's north island, Victoria and Tasmania. Very little is known of their range when not breeding, but they are thought to be fairly sedentary, remaining in coastal waters adjacent to colonies (del Hoyo et al. 1992). Its breeding season is variable according to locality, forming colonies with up to 1,500 individuals in burrows on steep slopes and also on flat ground of oceanic islands. It nests in burrows with an end chamber. Its diet comprises mainly of planktonic crustaceans, which are caught under water in pursuit-diving either from the surface or after plunging.