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Trindade Petrel Pterodroma arminjoniana

This species has a very small breeding range and population on two groups of islands in the south Atlantic Ocean, where it is susceptible to human impacts and stochastic events. An unidentifed Pterodroma species breeding on Round Island in the Indian Ocean is also now believed to be the same species based on recent genetic work (Brown and Jordan 2009). The species's status may now require re-evaluation.

Taxonomic source(s)
AERC TAC. 2003. AERC TAC Checklist of bird taxa occurring in Western Palearctic region, 15th Draft. Available at: # _the_WP15.xls#.
Brooke, M. de L. 2004. Albatrosses and Petrels Across the World. 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: #

35-39 cm. Medium-sized, polychromatic petrel (dark, pale and intermediate plumages) with diagnostic white patch on underwing at the bases of primary feathers.. Dark morph is wholly dark brown. Pale morph has very dark grey upperparts, white forehead-sides, and is white below with indistinct or well delimited grey breast-band. Black, deep and narrow bill, with strongly hooked nail, typical of the genus. Juvenile like adult. Similar spp. Dark morph is similar to Kermadec Petrel P. neglecta, but has pointed tail ,more white on underwing, but only separated from the Trindade petrel by absence of pale primary shafts in the upperwing and distinct call. Pale morph has less white on face and more on underwing than P. neglecta.

Distribution and population
Pterodroma arminjoniana breeds on Trindade and Martin Vaz Islands off the coast of Espírito Santo, Brazil. It was considered abundant on Trindade in 1913 and 1986 (Murphy 1936, Filippini 1986). Surveys in the mid-1990s have indicated that the Trindade population numbers 2,000-5,000 individuals (F. P. da Fonseca Neto in litt. 2000), and the global population was recently estimated at 15,000 individuals (Brooke 2004), although recent estimates suggest the total may be as low as 1,130 individuals (Luigi et al. 2008). Flocks have been noted flying around the Tunel, Pão de Açúcar, Farilhões and Crista de Galo peaks, but the most probable nest-sites are inaccessible without specialist equipment (Filippini 1986). It was first recorded breeding on the Martin Vaz Islands (three small islands and several associated stacks 45 km east of Trindade) in 1924-1925, when it was abundant on the middle island (Murphy 1936), although there is no recent evidence of breeding at this site (Luigi et al. 2008). Also recently identified, from what was previously an unidentified Pterodroma species, to be breeding on Round Island, 22 km north of Mauritius, in the Indian Ocean (Brown and Jordan 2009). There have been confirmed sightings of several birds at sea in the central south Atlantic (490 nm northeast of Tristan da Cunha), off the Azores and a single sighting off Cape Verde Islands (Flood 2010). Records suggest they may regularly forage in the central north Atlantic and in small numbers as far east as the Macaronesian islands (Flood 2010).

Population justification
Luigi et al. (2008) have revised the previous population estimate of 15,000 individuals globally (Brooke 2004) to just 1,130 indviduals.

Trend justification
Presumed to be stable, as there are no current major threats.

It breeds year-round (all months) in crevices and other cliff-cavities in the highest parts of Trindade (Antas 1991) but sometimes down to sea level. The peak times for breeding activities (laying) are October and April (F. P. da Fonseca Neto in litt. 2000).

Introduced cats and pigs may have formerly restricted the breeding population on Trindade to inaccessible cliff sites (see item 'Ecology' above) (Williams 1984, F. P. da Fonseca Neto in litt. 2000), and it is also a surface nesting species, so low altitude populations might have been eliminated by feral pigs, cats and humans from the 1700s onwards, except those in small islets surrounding the main island. Hundreds of goats (<500) and/or fire have largely removed forested habitats on the island (Murphy 1936, Olson 1981, F. P. da Fonseca Neto in litt. 2000), but the effect on breeding sites is undetermined. The Brazilian navy is possibly interested in building a small airbase on the island, which could pose threats in its construction and operation (F. P. da Fonseca Neto in litt. 2000). Experimental wind turbines and a tower for wind measurements have already been built on the island, with plans to build further wind turbines in the near future. The Martin Vaz Islands have never been inhabited and are unlikely to harbour introduced mammals (Williams 1984). The only disturbance to these populations has been the former use of the islands for occasional target practice by the navy (Williams 1984).

Conservation Actions Underway
Since 1967, Brazilian law has afforded protection to all seabirds by forbidding persecution, killing, colony disturbance and the use of bird by-products (Antas 1991). The navy eradicated goats from Trindade by 2005 and are restoring forested natural habitats (da Silva 1995, F. P. da Fonseca Neto in litt. 2000). Pigs and cats were eradicated from the island by 1970 (Williams 1984, F. P. da Fonseca Neto in litt. 2000). There is an ongoing study on the species's breeding biology (Murphy 1936, F. P. da Fonseca Neto in litt. 2000). Conservation Actions Proposed
Designate the majority of Trindade as a federal reserve (Antas 1991) or national park (F. P. da Fonseca Neto in litt. 2000). Determine the taxonomic status of the unidentified Pterodroma population on Round Island (Brooke et al. 2000). Conduct an impact assessment before any construction on Trindade.

Antas, P. T. Z. 1991. Status and conservation of seabirds breeding in Brazilian waters. In: Croxall, J.P. (ed.), Seabird status and conservation: a supplement, pp. 141-158. International Council for Bird Preservation, Cambridge, U.K.

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

Brooke, M. De L.; Imber, M. J.; Rowe, G. 2000. Occurrence of two surface-breeding species of Pterodroma on Round Island, Indian Ocean. Ibis 142: 154-158.

Brown, R. M.; Jordan, W. C. 2009. Characterization of polymorphic microsatellite loci from Round Island Petrels (Pterodroma arminjoniana) and their utility in other seabird species. Journal of Ornithology 150: 925-929.

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.

da Silva, G. L. 1995. Aspectos da biologia reprodutiva de Pterodroma arminjoniana (Giglioli & Salvadori, 1869) (Aves: Procellariidae) na Ilha de Trinidade, Atlantico Sul. Thesis. MSc, Museu Nacional-UFRJ, Rio de Janeiro.

Filippini, A. 1986. Relatório sobre a visita à Ilha da Trinidade.

Flood, B. 2010. More Trinidade Petrels around the Atlantic. Birding World 23(7): 305-306.

Luigi, G.; Bugoni, L.; Fonseca-Neto, F. P.; Teixeira, D. M. 2008. Biologia e conservação do petrel-de-trindade, Pterodroma arminjoniana, na ilha da Trindade, Atlântico sul. In: Mohr, L. V.; Castro, J. W. A.; Costa, P. M. S.; Alves, R. J. V. (ed.), Ilhas oceânicas brasileiras: da pesquisa ao manejo. Volume 2, Ministério do Meio Ambiente, Brasília.

Murphy, R. C. 1936. Oceanic birds of South America. American Museum of Natural History, New York.

Olson, S. L. 1981. Natural history of vertebrates on the Brazilian islands of the mid South Atlantic. National Geographic Society Research Reports 13: 481-492.

Pinguinhas, M. 2006. A pale morph Trinidade Petrel in the Azores. Birding World 19: 210-211.

Savigny, C.; Caille, G.; González, R.; Harris, G. 2005. The Trinidade Petrel (Pterodroma arminjoniana) at Golfo san Matías: a new species for Argentina. Hornero 20(2): 183-186.

Williams, A. J. 1984. Breeding distribution, numbers and conservation of tropical seabirds on oceanic islands in the South Atlantic Ocean. In: Croxall, J.P.; Evans, P.G.H.; Schreiber, R.W. (ed.), Status and conservation of the world's seabirds, pp. 393-401. International Council for Bird Preservation, Cambridge, U.K.

Further web sources of information
Australian Govt - Action Plan for Australian Birds 2000 - Recovery Outline

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
Anderson, O., Clay, R., Frere, E., Lascelles, B., Temple, H., Symes, A.

Bugoni, L., da Fonseca Neto, F.

IUCN Red List evaluators
Butchart, S., Taylor, J.

Recommended citation
BirdLife International (2014) Species factsheet: Pterodroma arminjoniana. Downloaded from on 01/10/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from on 01/10/2014.

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.

Additional resources for this species

ARKive species - Trindade petrel (Pterodroma arminjoniana) 0

Key facts
Current IUCN Red List category Vulnerable
Family Procellariidae (Petrels, Shearwaters)
Species name author (Giglioli & Salvadori, 1869)
Population size 1100-15000 mature individuals
Population trend Stable
Distribution size (breeding/resident) 1,130,000 km2
Country endemic? Yes
Links to further information
- Additional Information on this species