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

Taxonomic note

Callaeas cinereus and C. wilsoni (del Hoyo and Collar 2016) were previously lumped as C. cinereus following Sibley & Monroe (1990, 1993) and Turbott (1990).

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2022	Least Concern
2016	Near Threatened	C2a(i)
2012	Not Recognised
2008	Not Recognised
2004	Not Recognised
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	106,000 km2	medium
Area of Occupancy (breeding/resident)	7,000 km2
Number of locations	20-30	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	3000-6000, 5000 mature individuals	good	estimated	2020
Population trend	increasing	poor	estimated	-
Generation length	5.7 years	-	-	-
Number of subpopulations	20-30	-	-	-
Percentage of mature individuals in largest subpopulation	15-20%	-	-	-

Population justification: In 2020 the population was estimated at 2,079 pairs and is placed here in the band 3,000-6,000 mature individuals, with a best estimate of 5,000 (J. Innes in litt. 2022). The largest population on Little Barrier Island/Hauturu was estimated at 422 pairs in 2013. Other large populations numbering more than 100 pairs are in Te Urewera National Park and Waipapa Ecological Area of Pureora Forest Park; populations of more than 50 pairs are found at Kaharoa-Onaia (near Rotorua), Mangatutu (Pureora) and Mapara (King Country), and 19 other smaller populations are known (Scofield et al. 2020).

Trend justification: The population has significantly increased primarily owing to pest control and translocation, numbering just 330 pairs in 1999 but increasing to approximately 2,000 pairs in 2020 (J. Innes in litt. 2022). Populations continue to increase in areas of intensive conservation work (Robertson et al. 2021), and these increases now predominate as populations at unmanaged sites are now extinct or functionally extinct. The species is entirely conservation-dependent, each population requiring ongoing (preferably annual) control of introduced pest mammals, or protection against pest mammal invasion if on a pest-free island. Populations are surveyed annually up to 25 breeding pairs, followed by surveys each 3 years thereafter (Scofield et al. 2020).

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

Country/Territory	IBA Name
New Zealand	Te Hauturu-o-Toi Little Barrier Island

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Temperate	major	resident
Shrubland	Temperate	suitable	resident
Altitude	0 - 600 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%)		No decline		Past Impact
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Majority (50-90%)		Negligible declines		Past Impact
		Stresses Ecosystem degradation, Ecosystem conversion
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Capra hircus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Cervus elaphus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Felis catus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Mustela erminea	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Trichosurus vulpecula	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Ecosystem degradation, Reduced reproductive success

Purpose	Scale
Pets/display animals, horticulture	international

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Recommended citation
BirdLife International (2024) Species factsheet: North Island Kokako Callaeas wilsoni. Downloaded from https://datazone.birdlife.org/species/factsheet/north-island-kokako-callaeas-wilsoni on 21/12/2024.
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 21/12/2024.