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Sooty Shearwater Ardenna grisea

Justification
This species is classified as Near Threatened because although it has a very large global population it is thought to have undergone a moderately rapid decline owing to the impact of fisheries, the harvesting of its young and possibly climate change.

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.
Cramp, S.; Perrins, C. M. 1977-1994. Handbook of the birds of Europe, the Middle East and Africa. The birds of the western Palearctic. Oxford University Press, Oxford.
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 grisea (del Hoyo and Collar 2014) was previously placed in the genus Puffinus as P. griseus.

Synonym(s)
Ardenna grisea Christidis and Boles (2008), Puffinus griseus (Gmelin, 1789)

Distribution and population
Puffinus griseus is an abundant shearwater, breeding on islands off New Zealand, Australia and Chile, and the Falkland Islands (Malvinas). In Australia there are colonies on 17 islands (all of less than 1,000 pairs), southern Chile (many colonies, some up to 200,000 pairs and up to 4 million birds on Isla Guafo; Reyes-Arriagada et al. 2007) and the Falklands (10,000-20,000 pairs) and more than 80 colonies in New Zealand (totalling c.5 million pairs) (Marchant and Higgins 1990). In 1970-71, the Snares Islands colonies were estimated to support 2,750,000 breeding pairs (del Hoyo et al. 1992; Heather and Robertson 1997). The total world population is thought to be over 20 million birds (Heather and Robertson 1997). Although this is an extremely numerous species, there are persistent signs of a current decline (Brooke 2004). In New Zealand, the number of burrows in the largest colony (on the Snares islands) declined by 37% between 1969-1971 and 1996-2000, and burrow occupancy may also have declined, indicating that an overall population decline may have occurred (Warham and Wilson 1982; Scofield 2002). Elsewhere the mainland New Zealand, colonies are in decline and certain offshore colonies have not responded to predator control (Gaze 2000; Jones 2000). In the California Current, Sooty Shearwater numbers have fallen by 90% in the last 20 years (Veit et al. 1996). It remains uncertain whether this has resulted from population declines or distributional shifts (Spear and Ainley 1999).

Population justification
The global population is roughly estimated to number > c.20,000,000 individuals (Brooke, 2004), while national population estimates include: c.100-10,000 breeding pairs, c.50-1,000 individuals on migration and c.50-1,000 wintering individuals in China; >c.1,000 individuals on migration in Japan and >c.1,000 individuals on migration in Russia (Brazil 2009).

Trend justification
There are persistent signs of current decline in the global population (Brooke 2004), and the population trend is decreasing in North America (based on Breeding Bird Survey and/or Christmas Bird Count data: Butcher and Niven 2007) and in New Zealand (Clucas et al. 2008). Though the rate of decline of the whole population has not been quantified, moderately rapid population declines are suspected.

Ecology
It nests on islands and headlands in large colonies. Burrows are dug for breeding under tussock grass, low scrub and on the Snares Islands under Olearia forest. Birds typically do not return to their natal colonies until age four. It feeds on fish, crustacea and cephalopods, caught while diving. Short (1-3 days) and long (5-15 days) provisioning trips are made by parents; longer trips allow foraging along the Antarctic Polar Front, reducing competition close to breeding grounds and allowing vast colonies to persist.

Threats
Harvesting young birds or 'muttonbirding' currently accounts for the take of around a quarter of a million birds annually (del Hoyo et al. 1992; Heather and Robertson 1997), but is unlikely to account for the scale of the decline. Populations are no longer ravaged by pelagic drift-nets which formerly drowned up to 350,000 birds annually (Ogi et al. 1993). Longline fisheries are responsible for large numbers of deaths of this and many other seabird species. Some authorities postulate that the decline may be associated with climate change, as investigation into the biolgoical impact of recent climatic trends suggests eithe large-scale shifts in the forgaing distribution of the species during the boreal summer, or dramatic reductions in abundance and survival rate (Ainley et al 1995; Veit et al. 1996, 1997; Spear and Ainley 1999; Wahl and Tweit 2000; Oedekoven et al. 2001; Hyrenbach and Veit 2003; Veit et al. 1996). Rats (Rattus rattus and R. Norvegicus) have been shown to predate on eggs and chicks, altohough the extent of the impact is unknown (Jones et al. 2008).

Conservation Actions Underway
The species is monitored at some sites and has been extensively studied in parts of its range. Some breeding grounds are protected and have benefited from eradications of introduced predators. Conservation Actions Proposed
Continue monitoring key colonies and migration bottlenecks. Research the key threats driving declines and assess appropriate responses. Buffer important colonies against invasive species invasions.

Related state of the world's birds case studies

References
Ainley, D. , Veit, R. , Allen, S. , Spear, L. , and Pyle, P. 1995. Variations in marine bird communities of the California Current, 1986–1994. . California Cooperative Oceanic Fisheries Investigations Reports 36: 72-77.

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.

Clucas, R. J.; Fletcher, D. J.; Moller, H. 2008. Estimates of adult survival rate for three colonies of Sooty Shearwater (Puffinus griseus) in New Zealand. Emu 108(3): 237-250.

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

Gaze, P. 2000. The response of a colony of sooty shearwater (Puffinus griseus) and flesh-footed shearwater (P-carneipes) to the cessation of harvesting and the eradication of Norway rats (Rattus norvegicus). New Zealand Journal of Zoology 27(4 (SI)): 375-379.

Heather, B. D.; Robertson, H. A. 1997. The field guide to the birds of New Zealand. Oxford University Press, Oxford, UK.

Hyrenbach, K. D. , and Veit, R. R. 2003. Ocean warming and seabird communities of the southern Californian current system (1987–98): response at multiple temporal scales. Deep-sea Research. Part II, Topical Studies in Oceanography 50: 2537–2565.

Jones, C. 2000. Sooty shearwater (Puffinus griseus) breeding colonies on mainland South Island, New Zealand: evidence of decline and predictors of persistence. New Zealand Journal of Zoology 27(4 (SI)): 327-334.

Jones, H.P., Tershy, B.R., Zavaleta, E.S., Croll, D.A., Keitt, B.S., Finkelstein, M.E. and Howald, G.R. 2008. Severity of the effects of invasive rats on seabirds: a global review. Conservation Biology 22(1): 16-26.

Marchant, S.; Higgins, P. J. 1990. Handbook of Australian, New Zealand and Antarctic birds, 1: ratites to ducks. Oxford University Press, Melbourne.

Oedekoven, C., Ainley, D. G., and Spear, L. B. 2001. Variable responses of seabirds to change in marine climate: California Current, 1985-1994. Marine Ecology Progress Series 212: 265-281.

Ogi, H., Yatsu, A., Hatanaka, H. and Nitta, A. 1993. The mortality of seabirds by driftnet fisheries in the north Pacific. International North Pacific Fisheries Commission Bulletin 53: 499-518.

Reyes-Arriagada, R.; Campos-Ellwanger, P.; Schlatter, R. P.; Baduini, C. 2007. Sooty Shearwater (Puffinus griseus) on Guafo Island: the largest seabird colony in the world? Biodiversity and Conservation 16(4): 913-930.

Söhle, I. S., Robertson, C. J. R., Nicholls, D. G., Mouritsen, H., Frost, B. and Moller, H. 2007. Satellite tracking of Sooty Shearwaters (Puffinus griseus) during their pre-laying "exodus" and incubation. Notornis 54: 180-188.

Scofield, R. P., Christie, D. 2002. Beach patrol records indicate a substantial decline in sooty shearwater (Puffinus griseus) numbers. Notornis 49(3): 158-165.

Spear L. B.; Ainley D. G. 1999. Migration routes of sooty shearwaters in the Pacific Ocean. Condor 101: 205-218.

Spear, L. B., Ainley, D. G. 1993. Migration Routes of Sooty Shearwaters in the Pacific Ocean. Condor 101(2): 205-218.

Veit, R. R., Pyle, P. and McGowan, J. A. 1996. Ocean warming and long-term change in pelagic bird abundance within the California Current System. Mar. Ecol. Prog. Ser. 139: 11–18.

Veit, R.R., Pyle, P. & McGowan, J.A. 1996. Ocean warming and long-term change in pelagic bird abundance within the California Current System. Marine Ecology Progress Series 139(11–18).

Wahl, T. R. , and Tweit, B. 2000. Seabird abundances off Washington, 1972–1998. . Western Seabirds 31(2): 69–88.

Warham, J.; Wilson, G.J. 1982. The size of the Sooty Shearwater population at the Snares Islands, New Zealand. Notornis 29: 23-30.

Further web sources of information
Additional information is available on the distribution of the Sooty Shearwater from the Global Procellariiform Tracking Database (http://www.seabirdtracking.org)

Detailed species account from Birds in Europe: population estimates trends and conservation status (BirdLife International 2004)

Detailed species account from Birds in Europe: population estimates, trends and conservation status (BirdLife International 2004)

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
McClellan, R., Benstead, P., Bird, J., Symes, A.

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

Recommended citation
BirdLife International (2014) Species factsheet: Ardenna grisea. Downloaded from http://www.birdlife.org on 01/08/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 01/08/2014.

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 Near Threatened
Family Procellariidae (Petrels, Shearwaters)
Species name author (Gmelin, 1789)
Population size mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 204,000,000 km2
Country endemic? No
Links to further information
- Additional Information on this species