• 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
-	-	-

Red List history

Year	Category	Criteria
2023	Near Threatened	B1b(iii)+2b(iii)
2016	Near Threatened	A2bc;D2
2012	Near Threatened	A2bc;D2
2008	Near Threatened	A2b,c; D2
2004	Near Threatened
2000	Lower Risk/Near Threatened
1994	Lower Risk/Near Threatened
1988	Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	504 km2	medium
Area of Occupancy (breeding/resident)	504 km2
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	24000 mature individuals	poor	estimated	2015
Population trend	decreasing	poor	suspected	-
Generation length	2.99 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: Spatially explicit habitat models linked to density functions for R. longirostra predicted a contemporary population of 36,123 birds on Pohnpei (Oleiro and Kesler 2015), which is rounded here to 36,100 and equivalent to approximately 24,000 mature individuals.

Trend justification: Surveys in 1994 found significantly fewer individuals than in 1983 in both the lowland and uplands, with nearly 90% of the sightings on c.10% of the land area (Buden 2000). However, results from a comparison between these surveys (Engbring et al. 1990, Buden 2000) and detections from surveys in 2012 indicated a mean change in detection rates of -18% and +359%, respectively (Oleiro and Kesler 2015). Compared to Buden (2000), increasing detection rates were observed at lower elevation zones and a slight decline was observed above 600 m (-7%) (Oleiro and Kesler 2015). Despite this, the species is positively associated with upland old-growth forest (Oleiro 2014) and modelling of 1,000 future landscape scenarios by Oleiro and Kesler (2015) indicated a mean population decline of 3.6% (SD 7%) in R. longirostra populations during the next 100 years, with anthropogenic vegetation changes to undisturbed habitats most likely to drive declines. Global Forest Watch (2022) data are not available for Pohnpei such that estimating a rate of habitat clearance is not possible, but growing of sakau is widespread and currently considered the main cause of the island's upland deforestation (Ellis et al. 2018). Given predicted population declines, ongoing deforestation and increasing demand for sakau (Oleiro and Kesler 2015, Ellis et al. 2018), the species is suspected to be declining at a slow rate.

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	Pohnpei Watershed Forest Reserve

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	suitable	resident
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude	0 - 800 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Scale Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Climate change & severe weather	Habitat shifting & alteration	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Slow, Significant Declines		Low Impact: 4
		Stresses Ecosystem degradation
Climate change & severe weather	Storms & flooding	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Slow, Significant Declines		Low Impact: 4
		Stresses Ecosystem degradation
Residential & commercial development	Tourism & recreation areas	Timing		Scope		Severity		Impact
		Future		Minority (<50%)		Slow, Significant Declines		Low Impact: 3
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Long-billed White-eye Rukia longirostra. Downloaded from https://datazone.birdlife.org/species/factsheet/long-billed-white-eye-rukia-longirostra on 23/11/2024.
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 23/11/2024.