• 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. 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
2013	Vulnerable	D1+2
2012	Vulnerable	D1+2
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	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	80 km2	medium
Area of Occupancy (breeding/resident)	80 km2
Number of locations	1	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	360-2000,500-1000 mature individuals	medium	estimated	2015
Population trend	stable	medium	suspected	1998-2008
Generation length	4 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The population has most recently (in 2015) been estimated at 554-3,014 birds, or c.360-2,000 mature individuals based on point counts at 25 locations and extrapolated across the island (assuming 75% of habitat was suitable) using binomial mixture models  (Bond et al. 2019a). However, the species is very mobile across the island making accurate population estimates difficult (Oppel and Bond in litt. 2016, Bond et al. 2019a). The best estimate is here placed at 500-1,000 mature individuals given reports of the species's mobility.

Trend justification: The population in 1987 was estimated at 646-1,616 individuals (Graves 1992) when applied to the correct island area (see Bond et al. 2019a) and assuming the entire island was suitable. In 2015, the population size was estimated to be 554-3,014 birds assuming 75% of the island area was suitable. Although caution is exercised given the unreliability of estimating the population size of this species because it is so mobile (Bond et al. 2019a), these data suggest that the population has remained broadly stable. Although the species appears comparatively unimpacted by the presence of Pacific rats (Rattus exulans), such that even during an attempted eradication the population of V. stepheni did not substantially increase (unlike other species studied) (Bond et al. 2019a), it may suffer precipitously if larger Norway rats (R. novergicus) were accidentally introduced.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Pitcairn Islands (to UK)	extant	native	yes

Country/Territory	IBA Name
Pitcairn Islands (to UK)	Henderson Island

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Altitude	0 - 30 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
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 - Named species	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Rapid Declines		Medium Impact: 6
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Plasmodium relictum	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Rapid Declines		Medium Impact: 6
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus exulans	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Negligible declines		Medium Impact: 6
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Viral/prion-induced diseases - Avipoxvirus	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Rapid Declines		Medium Impact: 6
		Stresses Species mortality

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Recommended citation
BirdLife International (2024) Species factsheet: Henderson Lorikeet Vini stepheni. Downloaded from https://datazone.birdlife.org/species/factsheet/henderson-lorikeet-vini-stepheni 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.