• 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
-	C2a(ii)	C2a(i,ii); D1

Red List history

Year	Category	Criteria
2023	Endangered	C2a(ii)
2016	Endangered	C2a(ii)
2012	Endangered	C2a(ii)
2009	Critically Endangered	B1a+b(i,ii,iii); B2a+b(i,ii,iii)
2008	Critically Endangered
2004	Critically Endangered
2000	Critically Endangered
1996	Endangered
1994	Endangered
1988	Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	72 km2	medium
Area of Occupancy (breeding/resident)	72 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	300-400 mature individuals	poor	estimated	1984
Population trend	decreasing	poor	inferred	-
Generation length	2.99 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: This species has always been regarded as uncommon in its tiny range: one scientist who spent more than 14 months in the Chuuk Islands failed to see it entirely, and it may be largely restricted to Tol with only localised populations on the other islands (Brandt 1962). The population has not been robustly estimated since 1984 when bird surveys (Engbring et al. 1990) found it locally common on Tol South (382 individuals) and rare on Onei (19 individuals), Paata (32 individuals) and Polle (93 individuals). In total, this estimate of 530 individuals may roughly equate to c.350 mature individuals. There is no more recent population estimate; many of these sites have not been searched in recent years, with one record on Paata in 2007 and all observations since 2010 concentrated on Mt Winipot, Tol South (eBird 2023, M. O'Brien in litt. 2023). In the absence of more recent and complete data, the population is tentatively placed in the range 300-400 mature individuals. However, there is evidence that the species has likely declined since the 1984 estimate (see Population trend), and an up to date quantification of the population size is urgently required.

Trend justification: There is considerable concern and uncertainty surrounding this species, with no reliable monitoring data and no recent on-ground access to the population being possible. However, the species is dependent on old-growth stands of native forest which is subject to deforestation and contains non-native species (Engbring et al. 1990, SPREP 2001), has declined from its historic distribution and may continue to be under threat from population pressures (R. Davis in litt. 2023). In 1984 bird surveys (Engbring et al. 1990) found the species to be locally common on Tol South (with an estimated 382 individuals in total) and rare on Onei (19 individuals), Paata (32 individuals) and Polle (93 individuals). Many of these sites have not been searched in recent years, with all observations since 2010 concentrated on Mt Winipot, Tol South (eBird 2023, M. O'Brien in litt. 2023). Although methods vary, the number of birds seen during visits to Mt Winipot since 2010 suggest a decline from 1984 estimates (eBird 2023, M. O'Brien in litt. 2023). Additionally, no calls have been extracted from acoustic surveys carried out on Onei in 2022, and difficulties regarding access permissions has prevented surveys of the other Faichuk islands (M. O'Brien in litt. 2023). Precautionarily therefore, the population is inferred to be declining overall.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Micronesia, Federated States of	extant	native	yes

Country/Territory	IBA Name
Micronesia, Federated States of	Mount Winipot / Tol South
Micronesia, Federated States of	Onei Island
Micronesia, Federated States of	Pata Island
Micronesia, Federated States of	Polle Island

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Plantations	suitable	resident
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude	0 - 400 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Agro-industry farming	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Majority (50-90%)		Slow, Significant Declines		Past Impact
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Climate change & severe weather	Storms & flooding	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Boiga irregularis	Timing		Scope		Severity		Impact
		Future		Unknown		Unknown		Unknown
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Named species	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Teardrop White-eye Rukia ruki. Downloaded from https://datazone.birdlife.org/species/factsheet/teardrop-white-eye-rukia-ruki on 22/12/2024.
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 22/12/2024.