EN
Akiapolaau Hemignathus wilsoni



Taxonomy

Taxonomic note
Hemignathus wilsoni (del Hoyo and Collar 2016) was previously listed as H. munroi following AOU (1998 & supplements); Sibley & Monroe (1990, 1993).

Taxonomic source(s)
AOU. 1998. Check-list of North American birds. American Ornithologists' Union, Washington, D.C.
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.
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- B1ab(i,ii,iii,iv,v); C2a(ii) B1ab(i,ii,iii,iv,v); C1+2a(i); D1+2

Red List history
Year Category Criteria
2016 Endangered B1ab(i,ii,iii,iv,v); C2a(ii)
2013 Endangered B1ab(i,ii,iii,iv,v)
2012 Endangered B1ab(i,ii,iii,iv,v)
2008 Endangered B1a+b(i,ii,iii,iv,v)
2004 Endangered
2000 Endangered
1996 Endangered
1994 Endangered
1988 Threatened
Species attributes

Migratory status not a migrant Forest dependency High
Land mass type Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 910 medium
Number of locations 4 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 800 good estimated 1995
Population trend Decreasing good estimated -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 17 - - -
Decline (10 years/3 generation past and future) 17 - - -
Number of subpopulations 5 - - -
Largest subpopulations - - -
Generation length (yrs) 5.5 - - -

Population justification: In 1990-1995, surveys estimated a population of 1,163 individuals. This is rounded to an estimate of 1,200 individuals, roughly equivalent to 800 mature individuals.

Trend justification: Surveys in 1990-1995 suggested a decline of c.22.5% over the previous 13 years (Fancy et al. 1996). The Mauna Kea population became extinct in 2002 and the species has not been seen in Kona since the late 1990s (L. Pejchar in litt. 2007). Surveys from 1977 to 2003 indicate that the species may have declined in the Keauhou-Kulani area (Gorresen et al. 2005). In the Ka`u District of Hawai`i, surveys from 1976 to 2005 indicate that the species has been extirpated from habitat below 1,500 m, with no change in the density of populations at high elevations (Gorresen et al. 2007).


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
USA N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
USA Hamakua Forests
USA Kau Forest
USA Mauna Kea Mamane - Naio Forest
USA Mauna Loa-Kilauea Forests

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Dry major resident
Forest Subtropical/Tropical Moist Montane major resident
Altitude 1300 - 2100 m Occasional altitudinal limits (max) 2900 m

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Livestock farming & ranching - Small-holder grazing, ranching or farming Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Felis catus Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Named species Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant 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
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Problematic native species/diseases Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Viral/prion-induced diseases - Avipoxvirus Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Species mortality

Recommended citation
BirdLife International (2019) Species factsheet: Hemignathus wilsoni. Downloaded from http://www.birdlife.org on 13/12/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 13/12/2019.