VU
Henderson Island Fruit-dove Ptilinopus insularis



Taxonomy

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.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - D2

Red List history
Year Category Criteria
2022 Vulnerable D2
2016 Vulnerable D2
2012 Vulnerable D2
2008 Vulnerable D2
2004 Vulnerable
2000 Vulnerable
1996 Vulnerable
1994 Vulnerable
1988 Lower Risk/Least Concern
Species attributes

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

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 -
Population
Estimate Data quality Derivation Year of estimate
Population size 3000-4000 mature individuals good estimated 1992
Population trend stable medium estimated -
Generation length 3.9 years - - -
Number of subpopulations 1 - - -
Percentage of mature individuals in largest subpopulation 100% - - -

Population justification: Estimates over the past three decades have been broadly congruent. In 1987, the population was estimated at c.3,420 individuals (Graves 1992; adjusted to 3,070 individuals using the correct island area, and assuming 75% habitat suitability; Brooke and Jones 1995) and, in 1992, using a different technique, at c.3,150 (adjusted to 3,650 using correct island area). In 2015, the population at 25 point count localities was extrapolated to the area of suitable habitat, enumerating to a population size of 4,476-10,072 (Bond et al. 2019a). Because the latter estimate was based on detectability distances that were not empirically determined, the value from Brooke and Jones (1995)—who approximated territory size—is considered the most accurate determination of the number of mature individuals, set here to 3,000-4,000.

Trend justification: Although direct comparison is hampered by methodological differences, count data between 1987 and 2015 are comparable (Graves 1992, Brooke and Jones 1995, Bond et al. 2019a) and do not indicate any decline. Since 2015, there is no identified threat that may have caused a reduction, although it is acknowledged that the population size of this species moderately fluctuates in response to food availability (Brooke and Jones 1995).


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

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Pitcairn Islands (to UK) Henderson Island

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Lowland major resident
Altitude 0 - 330 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
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 rattus 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 - 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

Recommended citation
BirdLife International (2024) Species factsheet: Henderson Island Fruit-dove Ptilinopus insularis. Downloaded from https://datazone.birdlife.org/species/factsheet/henderson-island-fruit-dove-ptilinopus-insularis 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.