email a friend
printable version
LC
Wedge-tailed Shearwater Ardenna pacifica

Justification
This species has an extremely 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.

Taxonomic source(s)
AERC TAC. 2003. AERC TAC Checklist of bird taxa occurring in Western Palearctic region, 15th Draft. Available at: #http://www.aerc.eu/DOCS/Bird_taxa_of _the_WP15.xls#.
Brooke, M. de L. 2004. Albatrosses and Petrels Across the World. Oxford University Press, Oxford.
Christidis, L.; Boles, W. E. 2008. Systematics and taxonomy of Australian birds. CSIRO Publishing, Collingwood, Australia.
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.
SACC. 2006. A classification of the bird species of South America. Available at: #http://www.museum.lsu.edu/~Remsen/SACCBaseline.html#.
Turbott, E. G. 1990. Checklist of the birds of New Zealand. Ornithological Society of New Zealand, Wellington.

Taxonomic note
Ardenna pacifica (del Hoyo and Collar 2014) was previously placed in the genus Puffinus as P. pacificus.

Synonym(s)
Ardenna pacifica Christidis and Boles (2008), Puffinus pacificus (Gmelin, 1789)

Distribution and population
The Wedge-tailed Shearwater ranges across from throughout the tropical Pacific and Indian Ocean roughly between latitudes 35°N and 35°S, breeding on a large number of oceanic islands and on the east and west coasts of Australia (del Hoyo et al. 1992).

Population justification
Brooke (2004) estimated the global population to number > c.5,200,000 individuals, while national population sizes have been estimated at c.50-10,000 individuals on migration in Taiwan and c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in Japan (Brazil 2009).

Trend justification
The population is suspected to be in decline owing to unsustainable levels of exploitation, persecution, predation by invasive species and the over-exploitation of tuna fisheries (Brooke 2004).

Ecology
This marine species can nearly always be found over pelagic waters except when at colonies. It feeds mostly on fish, with some cephaolopods, crustaceans and insects. It catches prey mainly on the wing by dipping but also by surface-seizing or pursuit-plunging. It will congregate with other seabirds and dolphins when around schooling fish, and will often attend trawlers and smaller fishing boats. Its breeding season is very variable nesting in burrows in colonies on offshore islands or atolls (del Hoyo et al. 1992).

References
Brazil, M. 2009. Birds of East Asia: eastern China, Taiwan, Korea, Japan, eastern Russia. Christopher Helm, London.

Brooke, M. De L. 2004. Albatrosses and petrels across the world. Oxford University Press, Oxford.

del Hoyo, J.; Elliot, A.; Sargatal, J. 1992. Handbook of the Birds of the World, vol. 1: Ostrich to Ducks. Lynx Edicions, Barcelona, Spain.

Further web sources of information
Explore HBW Alive for further information on this species

Search for photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Ekstrom, J., Butchart, S., Newton, P., Calvert, R.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2014) Species factsheet: Ardenna pacifica. Downloaded from http://www.birdlife.org on 23/10/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 23/10/2014.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Key facts
Current IUCN Red List category Least Concern
Family Procellariidae (Petrels, Shearwaters)
Species name author (Gmelin, 1789)
Population size mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 115,000,000 km2
Country endemic? No
Links to further information
- Additional Information on this species