|Scientific Name:||Ardenna gravis (O'Reilly, 1818)|
Ardenna gravis ssp. gravis — Christidis and Boles (2008)
Puffinus gravis (O'Reilly, 1818)
|Taxonomic Source(s):||del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.|
|Taxonomic Notes:||Ardenna gravis (del Hoyo and Collar 2014) was previously placed in the genus Puffinus.|
|Identification information:||47$cm. Large, distinctly capped shearwater, mainly of the Atlantic. Dark blackish brown cap and white hind-neck create capped appearance. Brown back, upperwing and rump; paler fringes to feathers produce scaled effect. White rear uppertail-coverts. Dark brown tail. White underparts except for variable brown belly patch (can be difficult to see). White underwing except for dark trailing edge and wingtip. Pink legs and feet but for black outer side to tarsus and outer toe. Dark grey bill. Similar spp. Cory's Shearwater Calonectris diomedea is less obviously capped and has paler bill plus more extensive dark area under the wing tip.|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer(s):||Butchart, S. & Symes, A.|
|Facilitator/Compiler(s):||Butchart, S., Ekstrom, J. & Newton, P.|
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). The population trend appears to be stable, and hence the species does not 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.
|Previously published Red List assessments:|
|Range Description:||This species breeds at three main sites: Nightingale and Inaccessible islands in the Tristan da Cunha group, and Gough Island, Tristan da Cunha (to UK) (Snow and Perrins 1998, Carboneras 1992d). Birds also breed in small numbers in the Falkland Islands (Malvinas), where the only confirmed site is Kidney Island (no more than 15 pairs recorded in 1987 (Woods 1988)), though there is a slight possibilty of breeding near Wineglass Hill, East Falkland, where one has been caught (Woods and Woods 1997).|
Native:Bermuda; Brazil; Chile; Falkland Islands (Malvinas); France; Greenland; Guyana; Ireland; Martinique; Mexico; Portugal; Saint Helena, Ascension and Tristan da Cunha; Saint Pierre and Miquelon; Spain (Canary Is.); United Kingdom; United States
Vagrant:Algeria; Angola; Australia; Barbados; Bonaire, Sint Eustatius and Saba; Cayman Islands; Curaçao; Denmark; Dominica; Dominican Republic; Gabon; Germany; Ghana; Gibraltar; Guadeloupe; Israel; Italy; Lebanon; Liberia; Morocco; Netherlands; Saint Lucia; Sao Tomé and Principe; Sint Maarten (Dutch part); Suriname; Sweden; Trinidad and Tobago; Virgin Islands, British; Virgin Islands, U.S.
Present - origin uncertain:Anguilla; Antigua and Barbuda; Argentina; Bahamas; Canada; Cape Verde; Côte d'Ivoire; Faroe Islands; French Guiana; Gambia; Grenada; Guinea; Guinea-Bissau; Iceland; Mauritania; Namibia; Norway; Puerto Rico; Saint Martin (French part); Saint Vincent and the Grenadines; Senegal; Sierra Leone; South Africa; South Georgia and the South Sandwich Islands; Turks and Caicos Islands; Uruguay; Venezuela, Bolivarian Republic of; Western Sahara
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Brooke (2004) estimated the global population to number at least 15,000,000 individuals. A minimum of 5,000,000 pairs are thought to breed at Tristan da Cunha, and 600,000 to 3,000,000 pairs at Gough (Carboneras 1992d).|
Trend Justification: The population is suspected to be stable in the absence of evidence for any declines or substantial threats.
|Current Population Trend:||Stable|
|Habitat and Ecology:||Adults begin a transequatorial migration in April, moving north-west to South America, up to Canada, past Greenland and onto the north-east Atlantic before returning south in November to the breeding islands (Carboneras 1992d, Harrison 1983). The species breeds on sloping ground, mainly in areas of tussock grass or Phylica woodland. It feeds mostly on fish, squid and fish offal (attending trawlers, sometimes in large numbers), and also on some crustaceans (Carboneras 1992d).|
|Continuing decline in area, extent and/or quality of habitat:||Unknown|
|Generation Length (years):||18.3|
|Movement patterns:||Full Migrant|
|Congregatory:||Congregatory (and dispersive)|
|Major Threat(s):||Several thousand adults and c.50,000 chicks are harvested every year from Nightingale Island by Tristan Islanders, which could lead to the collapse of the population without research into sustainable harvesting levels (Carboneras 1992d). Although there is no real evidence of threats to the tiny confirmed Falkland breeding population, predation by feral cats at Wineglass Hill would be a threat to any breeding there (R. Woods in litt. 1999).|
|Amended reason:||Map revised.|
Brooke, M. de L. 2004. Albatrosses and Petrels Across the World. Oxford University Press, Oxford.
Carboneras, C. 1992. Procellariidae (Petrels and Shearwaters). In: del Hoyo, J.; Elliott, A.; Sargatal, J. (ed.), Handbook of the birds of the world, pp. 216-257. Lynx Edicions, Barcelona, Spain.
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
Harrison, P. 1985. Seabirds: an identification guide. Christopher Helm, London.
IUCN. 2016. The IUCN Red List of Threatened Species. Version 2016-3. Available at: www.iucnredlist.org. (Accessed: 07 December 2016).
IUCN. 2017. The IUCN Red List of Threatened Species. Version 2017-1. Available at: www.iucnredlist.org. (Accessed: 27 April 2017).
Snow, D.W. and Perrins, C.M. 1998. The Birds of the Western Palearctic, Volume 1: Non-Passerines. Oxford University Press, Oxford.
Woods, R. W.; Woods, A. 1997. Atlas of breeding birds of the Falkland Islands. Anthony Nelson, Oswestry, U.K.
|Citation:||BirdLife International. 2017. Ardenna gravis. (amended version published in 2016) The IUCN Red List of Threatened Species 2017: e.T22698201A110674071.Downloaded on 21 October 2017.|
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