• 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
B1ab(i,ii,iii,v); C1	A2bce+3bce+4bce; B1ab(i,ii,iii,v)+2ab(i,ii,iii,v); C1; D	A2bce+3bce+4bce; B1ab(i,ii,iii,v)+2ab(i,ii,iii,v); C1; D1+2

Red List history

Year	Category	Criteria
2023	Critically Endangered	B1ab(i,ii,iii,v); C1
2016	Critically Endangered	B1ab(iii)
2015	Critically Endangered	B1ab(iii)
2013	Critically Endangered	B1ab(iii)
2012	Critically Endangered	B1ab(iii)
2010	Critically Endangered	B1a+b(iii)
2009	Critically Endangered	B1a+b(iii)
2008	Critically Endangered
2004	Critically Endangered
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)	70 km2	medium
Area of Occupancy (breeding/resident)	40 km2
Number of locations	1	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	105 mature individuals	medium	estimated	2017
Population trend	decreasing	poor	estimated	2017-2027
Rate of change over the past 10 years/3 generations (longer of the two periods)	60-70%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	60-70%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	60-70%	-	-	-
Generation length	2.81 years	-	-	-
Number of subpopulations	2	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

Population justification: During 1976-1983, it was estimated to number c.500 individuals, of which 71% (c. 355) occurred above 1,500 m (Scott et al. 1986). Density surveys in 1997 and 2001 suggested similar numbers in the 35 km² of remaining suitable habitat above 1,525 m (Simon et al. 1997, D. Leonard in litt. 2012). The total population size was estimated to number 513 ± 143 individuals in 1980, 447 ± 157 in 1992, 544 ± 153 in 2001 and 291 ± 69 in 2011 (Judge et al. 2021). Overall density was even lower in 2017 (0.05 ± 0.02 birds/ha), with an estimated total abundance of 157 ± 67 (95% CI 44–312) individuals in their 2,992 ha range (Judge et al. 2021). This is roughly equivalent to 105 mature individuals.

Trend justification: Since 2001 the population has declined by approximately 71%  to 157 ± 67 individuals in 2017 (Judge et al. 2021). Surveys suggest a c.46% decline in the period 2011-2017, roughly equivalent to 64% in ten years (Judge et al. 2021), and this is thought to be continuing given that the threats are ongoing. The current rate of decline is therefore placed in the band 60-70% in ten years. The current estimated range is projected to decline by >75% by 2100 according to climate-based models (Fortini et al. 2015), although the population is likely to become functionally extinct in as few as ten years if current population trajectories continue (Mounce et al. 2018).

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

Country/Territory	IBA Name
USA	Haleakala

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude	1200 - 2350 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Livestock farming & ranching - Agro-industry grazing, ranching or farming	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Majority (50-90%)		Slow, Significant Declines		Past Impact
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	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	Habitat shifting & alteration	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Slow, Significant Declines		Medium Impact: 7
		Stresses Indirect ecosystem effects, Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Axis axis	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Capra hircus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Felis catus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Hedychium gardnerianum	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Herpestes auropunctatus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses 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 Competition, Reduced reproductive success, Species mortality
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 - Psidium cattleianum	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		No decline		Low Impact: 4
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Sus domesticus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Indirect ecosystem effects, Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Competition, Species mortality
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 Competition, Species mortality
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Asio flammeus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		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

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Recommended citation
BirdLife International (2024) Species factsheet: Maui Parrotbill Pseudonestor xanthophrys. Downloaded from https://datazone.birdlife.org/species/factsheet/maui-parrotbill-pseudonestor-xanthophrys 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.