Justification of Red List Category
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Brooke (2004) estimated the global population to number 8,000,000-10,000,000 individuals.
The population is suspected to be in decline owing to predation by invasive species.
The Black-winged Petrel breeds in the south-west Pacific, from Lord Howe Island (Australia) and eastern Australia in the west, New Caledonia in the north, the Chatham Islands (New Zealand) in the south and Austral Islands (French Polynesia) in the east. 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.
This species is marine and highly pelagic, avoiding land except during breeding. 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 Procellariiformes. It breeds in colonies on oceanic islands, usually making burrows on high ground inland amongst scrub or tussock grass (del Hoyo et al. 1992).
Volcanoes represent a genuine threat to this species, with Macauley Island, containg 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. Cats represent a predation risk to the Black-winged Petrel, and have been noted to have prevented the establishment of Black-winged Petrel on multiple occassions (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 were 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.
Text account compilers
Calvert, R., Fjagesund, T., Butchart, S., Hermes, C., Ekstrom, J., Martin, R., Stuart, A.
BirdLife International (2019) Species factsheet: Pterodroma nigripennis. Downloaded from http://www.birdlife.org on 16/06/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/06/2019.