• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

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.

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

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

	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	-

	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	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

Country/Territory	IBA Name
New Zealand	Chatham (offshore)
New Zealand	Chatham Islands (nearshore)
New Zealand	Rangatira South East Island
New Zealand	Tuku

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

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

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

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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 23/11/2024.
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 23/11/2024.