VU
Chatham Islands Petrel Pterodroma axillaris



Taxonomy

Taxonomic source(s)
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. 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.
Turbott, E.G. 1990. Checklist of the Birds of New Zealand. Ornithological Society of New Zealand, Wellington.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - A2be+4be; D2

Red List history
Year Category Criteria
2018 Vulnerable A2be+4be; D2
2016 Vulnerable A2be+4be; D2
2015 Vulnerable A2be+4be; D2
2013 Endangered A2bde+4bde
2012 Endangered A2bde+4bde
2010 Endangered A2b,d,e; C2a(ii)
2009 Endangered A2b,c,e; C2a(ii)
2008 Critically Endangered
2007 Critically Endangered
2006 Critically Endangered
2004 Critically Endangered
2000 Critically Endangered
1996 Critically Endangered
1994 Critically Endangered
1988 Threatened
Species attributes

Migratory status full migrant Forest dependency medium
Land-mass type Average mass -
Range

Estimate Data quality
Extent of Occurrence (breeding/resident) 46,200,000 km2 medium
Area of Occupancy (breeding/resident) 2 km2 medium
Number of locations 3 -
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 1100 mature individuals medium estimated 2010
Population trend increasing medium estimated 1973-2020
Rate of change over the past 10 years/3 generations (longer of the two periods) 30-49% - - -
Rate of change over the past & future 10 years/3 generations (longer of the two periods) 30-49% - - -
Generation length 15.6 years - - -
Number of subpopulations 1 - - -
Percentage of mature individuals in largest subpopulation 100% - - -

Population justification: Based on an age at first breeding of three years, and an estimate that at least 75% of birds will be over three years old, the latest total population estimate from 2010 of c. 1,400 individuals probably includes c. 1,100 mature individuals (Gummer et al. 2015).

Trend justification: Occupied burrows and the number of surface birds declined at areas in common usage in the 1930s, into the 1990s. Intense, sometimes lethal, competition with Broad-billed Prions Pachyptila vittata for burrow space precipitated recent declines, crudely estimated at 1% per annum equating to approximately 50% over the past three generations. Since 1997, however, control of prions at known petrel burrows, a practice replaced by use of burrow flaps since 2001, has greatly improved nesting success and the population is now increasing; a trend boosted by two recent and successful translocations to predator free conservation covenants on Pitt Island and Chatham Island. The total population has now recovered from 600-800 birds in 1995 to about 1,400 birds in 2010 (based on mark-recapture and burrow survey analysis) (Gummer et al. 2015). The population continues to increase and birds have been colonising formerly occupied parts of South East Island (G. Taylor in litt. 2012, K.J. Wilson in litt. 2012). Although dependent on conservation action, the continued population increase makes it likely that the population size reduction over the past three generations (47 years) is now less than 50% (G. Taylor in litt. 2012). However the reduction is still likely to be greater than 30%.


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Chile extant native yes
High Seas extant native yes
New Zealand extant native yes
Peru extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
New Zealand Chatham (offshore)
New Zealand Chatham Islands (nearshore)
New Zealand Rangatira South East Island
New Zealand Tuku

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Temperate major breeding
Marine Neritic Pelagic suitable breeding
Marine Neritic Pelagic suitable non-breeding
Marine Oceanic Epipelagic (0-200m) major non-breeding
Marine Oceanic Epipelagic (0-200m) major breeding
Shrubland Temperate major breeding
Altitude   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 Majority (50-90%) Rapid Declines Past Impact
Stresses
Species mortality
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Future Whole (>90%) Unknown Unknown
Stresses
Indirect ecosystem effects, Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Canis familiaris Timing Scope Severity Impact
Ongoing Minority (<50%) No decline Low Impact: 4
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Felis catus Timing Scope Severity Impact
Ongoing Minority (<50%) No decline Low Impact: 4
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Sus domesticus Timing Scope Severity Impact
Ongoing Minority (<50%) No decline Low Impact: 4
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Problematic native species/diseases - Pachyptila vittata Timing Scope Severity Impact
Ongoing Whole (>90%) Negligible declines Medium Impact: 6
Stresses
Competition, Reduced reproductive success, Species mortality

Utilisation
Purpose Scale
Food - human subsistence, national
Food - human subsistence, national

Recommended citation
BirdLife International (2024) Species factsheet: Chatham Islands Petrel Pterodroma axillaris. Downloaded from https://datazone.birdlife.org/species/factsheet/chatham-islands-petrel-pterodroma-axillaris on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/12/2024.