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

Taxonomic note
Since 1930 commonly treated as a subspecies of C. auriceps, and clearly the two are closely related; present species differs, however, in its considerably larger size, with mean male wing 128.2 (n=6) vs 109.9 (n=10) (Forshaw 1989) (at least 2), its lack of red line between frons and eye (2), outer webs of flight-feathers greenish-blue vs violet-blue (2), and more yellowish underparts (1). Has hybridized extensively with C. novaezelandiae chathamensis, to the extent that it was almost eradicated by genetic swamping (Chan Chi-hang et al. 2005, Chan Chi-hang et al. 2006, Triggs and Daugherty 1996). Monotypic.

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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	D1+2

Red List history

Year	Category	Criteria
2022	Vulnerable	D1+2
2016	Vulnerable	D1+2
2012	Endangered	D
2008	Endangered	D1
2004	Endangered
2000	Endangered
1994	Not Recognised
1988	Not Recognised

Migratory status	not a migrant	Forest dependency	high
Land-mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	12 km2	medium
Area of Occupancy (breeding/resident)	12 km2	good
Number of locations	2	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	250-999 mature individuals	poor	estimated	2021
Population trend	stable	medium	estimated	-
Generation length	3.65 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The population of forbesi-like phenotypes has increased dramatically on Mangere Island in the past as a result of habitat management and exotic predator control. The Little Mangere Island population is poorly known due to few visits taking place (H. Aikman in litt. 1999). In 1999, the total population was estimated to be about 120 birds (Aikman et al. 2001), but surveys in 2003 estimated 900 individuals on Mangere Island (Aikman and Miskelly 2004, D. Houston and C. Miskelly in litt. 2008) following culling of Cyanoramphus novaezelandiae. Since then it has likely decreased to 600-700 mature individuals with rapid regeneration and planting of vegetation (T. Greene in litt. 2020). A survey in 2011 assessed the phenotypes of concern to be at 10%, the trigger level for management action (D. Houston in litt. 2012) but number of hybrids appear to have stabilised or declined since (T. Greene in litt. 2020). The population has exceeded 250 mature individuals for well over 5 years and is currently thought to be stable (Robertson et al. 2021), so it is placed in the range of 250-999 mature individuals.

Trend justification: Habitat management and predator control has caused the species to dramatically increase in the past, and it is now considered to be stable. The population has shown minor fluctuations due to both habitat restoration and hybridisation as the species recolonised Mangere Island by the 1970s. Overall, the population is estimated to have been stable over the last three generations (Robertson et al. 2013, 2017, 2021).

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
New Zealand	extant	native		yes

Country/Territory	IBA Name
New Zealand	Mangere

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Temperate	major	resident
Shrubland	Temperate	major	resident
Altitude	0 - 287 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Livestock farming & ranching - Small-holder grazing, ranching or farming	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Majority (50-90%)		Slow, Significant Declines		Past Impact
		Stresses Ecosystem degradation, Ecosystem conversion
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 - Felis catus	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Minority (<50%)		Negligible declines		Past Impact
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Very Rapid Declines		Medium Impact: 7
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Cyanoramphus novaezelandiae	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Hybridisation
Natural system modifications	Fire & fire suppression - Increase in fire frequency/intensity	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Majority (50-90%)		Rapid Declines		Past Impact
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Chatham Islands Parakeet Cyanoramphus forbesi. Downloaded from https://datazone.birdlife.org/species/factsheet/chatham-islands-parakeet-cyanoramphus-forbesi 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.