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

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
2023	Near Threatened	B1b(iii)+2b(iii); D2
2016	Vulnerable	D1+2
2012	Vulnerable	D1+2
2010	Vulnerable	D1; D2
2008	Vulnerable	D1; D2
2004	Vulnerable
2000	Vulnerable
1996	Vulnerable
1994	Vulnerable
1988	Threatened

Migratory status	not a migrant	Forest dependency	high
Land-mass type		Average mass	83 g

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	50 km2	medium
Area of Occupancy (breeding/resident)	48 km2
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	2350 mature individuals	medium	estimated	2010
Population trend	stable	poor	suspected	-
Generation length	4.07 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The population was estimated at 2,350 mature individuals in 2010 (based on distance sampling in nine inland valleys, density averaging at 0.5 per hectare), and it is reported to be relatively localised and not evenly distributed (Easby 2011, Easby and Compton 2013, Thibault and Cibois 2017).

Trend justification: The population trend has not been assessed directly. The species seems to have declined in the lowlands in the 1970s possibly owing to aggressive competition from the introduced Common Myna Acridotheres tristis, however this is not currently considered to be a serious threat (Thibault and Cibois 2017). The species remains abundant in suitable habitat and there is no evidence for substantial declines (Easby and Compton 2013, Thibault and Cibois 2017, G. McCormack in litt. 2023). As such, the species is tentatively suspected to be stable overall, but up-to-date surveys are urgently required.

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

Country/Territory	IBA Name
Cook Islands	Takitumu Conservation Area, Rarotonga

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	suitable	resident
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude	150 - 600 m	Occasional altitudinal limits	(min) 30 m

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Shifting agriculture	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	Storms & flooding	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Rapid Declines		Low Impact: 5
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Acridotheres tristis	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		No decline		Low Impact: 5
		Stresses Species disturbance
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		No decline		Low Impact: 5
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		No decline		Low Impact: 5
		Stresses Ecosystem degradation
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Majority (50-90%)		Slow, Significant Declines		Past Impact
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Rarotonga Starling Aplonis cinerascens. Downloaded from https://datazone.birdlife.org/species/factsheet/rarotonga-starling-aplonis-cinerascens 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.