EN
Oahu Elepaio Chasiempis ibidis



Taxonomy

Taxonomic note

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.

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

Red List history
Year Category Criteria
2016 Endangered B1ab(i,ii,iii,iv,v)
2012 Endangered B1ab(i,ii,iii,iv,v)
2011 Endangered B1a+b(i,ii,iii,iv); C2a(i)
2008 Not Recognised
2004 Not Recognised
2000 Not Recognised
1994 Not Recognised
1988 Not Recognised
Species attributes

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

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 1,100 good
Number of locations -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 1261 good estimated 2001
Population trend Decreasing poor 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) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations 2-100 - - -
Percentage in largest subpopulation - - -
Generation length (yrs) 5.9 - - -

Population justification: The total population was estimated at 1,261 mature individuals (95% CI=1, 205 - 1, 317) following surveys conducted from 2011-2012 (VanderWerf et al. 20013), consisting of about 477 breeding pairs and 307 single males. This total includes 592 males (95% CI= 554-630) and 369 females in the Ko'olau Mountains and 192 males and 84 females in the Wai' anae Mountains (VanderWerf et al. 2011, 2013).

Trend justification: Surveys conducted in the 1990s produced evidence that the species had declined by more than 75% since 1975 and by approximately 96% since the arrival of humans (VanderWerf et al. 2001). The species's population is still in decline owing to the effects of disease, introduced species and ongoing habitat loss and degradation. Bayesian modelling demonstrate rapid population collapse for this species (Aagaard et al. 2016). Surveys in 2006-2010 showed that the number of birds in the Waianae Mountains, which had supported half the population, had declined to only 300 birds (VanderWerf et al. 2011a).


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 Oahu Uplands

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Dry major resident
Forest Subtropical/Tropical Moist Lowland major resident
Forest Subtropical/Tropical Moist Montane major resident
Altitude 200 - 800 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Agro-industry farming 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 - Plasmodium relictum Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
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%) Rapid Declines Medium Impact: 7
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%) Negligible declines Low Impact: 5
Stresses
Ecosystem degradation
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
Reduced reproductive success, Species mortality
Natural system modifications Fire & fire suppression - Increase in fire frequency/intensity Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation
Residential & commercial development Housing & urban areas Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2022) Species factsheet: Chasiempis ibidis. Downloaded from http://www.birdlife.org on 06/12/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 06/12/2022.