Atlantic Petrel Pterodroma incerta


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. and 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. 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.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: #http://www.museum.lsu.edu/~Remsen/SACCBaseline.htm#.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- B2ab(v) A2be+3be+4be; B2ab(v); D2

Red List history
Year Category Criteria
2018 Endangered B2ab(v)
2016 Endangered B2ab(v)
2012 Endangered B2ab(v)
2010 Endangered B2a+b(v)
2008 Endangered B2a+b(v)
2007 Vulnerable
2006 Vulnerable
2004 Vulnerable
2000 Vulnerable
1996 Vulnerable
1994 Vulnerable
1988 Lower Risk/Least Concern
Species attributes

Migratory status full migrant Forest dependency Does not normally occur in forest
Land mass type Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 23,300,000 medium
Extent of Occurrence breeding/resident (km2) 64 good
Number of locations 2 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 1800000 medium estimated 2001
Population trend Decreasing poor inferred -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 30-49 - - -
Decline (10 years/3 generation past and future) 30-49 - - -
Number of subpopulations 2 - - -
Largest subpopulations 100 - - -
Generation length (yrs) 15.6 - - -

Population justification:

On Gough Island, Cuthbert (2004) estimated 1.8 million breeding pairs in 2001, suggesting a world population of around 5 million birds. The population size was re-estimated by Rexer-Huber et al. (2014), taking into account the occupancy rates of suitable burrows in 2010 and 2012. This new estimate indicates a population size of 860,000 pairs, varying between 630,000 and 1,100,000 pairs. Because occupancy rates varied interannually, the species’s total breeding area could only be estimated crudely, and burrow densities were assumed to be similar throughout the habitat. This estimate should, therefore, be treated with caution. 

Trend justification: Stochastic population models computing a breeding success of 24.7% and parameters estimated for other gadfly petrels (adult survival = 93%, immature survival = 79% and recruitment age = 6 years) suggest a population decline of 0.7% per annum (Wanless et al. 2012). This would equate to a decline of 28% over three generations (c. 47 years). However, given that breeding success seems to be less than 20% (Cuthbert and Hilton 2004, Wanless et al. 2012, Dilley et al. 2015) and that survival rates did not take into account predation by Subantarctic Skuas Catharacta antarctica and thus were probably over-estimated, the population might be decreasing at a faster rate. Therefore, declines are placed here in the range 30-49% over three generations.

Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Antarctica V Extant
Argentina N Extant Yes
Brazil N Extant Yes Yes
Falkland Islands (Malvinas) N Extant Yes
Israel V Extant
Jordan V Extant
Namibia N Extant Yes
South Africa N Extant Yes
South Georgia & the South Sandwich Islands V Extant
St Helena (to UK) N Extant Yes
Uruguay N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
St Helena (to UK) Gough Island
St Helena (to UK) Tristan Island

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Marine Neritic Pelagic major non-breeding
Marine Neritic Pelagic major breeding
Marine Oceanic Epipelagic (0-200m) major non-breeding
Marine Oceanic Epipelagic (0-200m) major breeding
Shrubland Temperate major breeding
Altitude 50 - 700 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Past, Unlikely to Return Minority (<50%) Rapid Declines Past Impact
Species mortality
Climate change & severe weather Storms & flooding Timing Scope Severity Impact
Ongoing Minority (<50%) Causing/Could cause fluctuations Low Impact: 5
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Mus musculus Timing Scope Severity Impact
Ongoing Whole (>90%) Very Rapid Declines High Impact: 9
Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Rattus exulans Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Reduced reproductive success
Invasive and other problematic species, genes & diseases Problematic native species/diseases - Catharacta antarctica Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Species mortality
Pollution Excess energy - Light pollution Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Species mortality

Purpose Primary form used Life stage used Source Scale Level Timing
Food (human) Whole Adults and juveniles Wild Non-trivial Recent
Food - human - - Non-trivial Recent

Recommended citation
BirdLife International (2019) Species factsheet: Pterodroma incerta. Downloaded from http://www.birdlife.org on 18/11/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 18/11/2019.