• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Taxonomic note
Sometimes treated as conspecific with Z. uropygialis; both sometimes considered closely related to Z. chloris and Z. citrinella. Monotypic.

Taxonomic source(s)
Handbook of the Birds of the World and BirdLife International. 2023. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 8. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v8_Dec23.zip.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2023	Least Concern
2016	Near Threatened	B1ab(iii)
2013	Near Threatened	B1ab(iii)
2012	Near Threatened	B1ab(iii)
2008	Near Threatened	B1a+b(iii)
2004	Near Threatened
2000	Lower Risk/Near Threatened
1994	Lower Risk/Near Threatened
1988	Near Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	880 km2	medium
Area of Occupancy (breeding/resident)	820 km2
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend	stable	-	suspected	-
Generation length	2.86 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The population size of this species has not been quantified, but it is described as fairly common in all wooded habitats, including open woodland and gardens (Eaton et al. 2021), and appears to be among the most commonly observed species on Kai Besar (eBird 2022). Nonetheless, given the island is just 550 km² in size, its population size may be moderately small.

Trend justification: In the ten years to 2022, forest loss on Kai Besar was less than 2% (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). Given this species' tolerance of open woodland and gardens, it is not thought that this level of habitat loss and degradation is likely to be impacting the species. Although its occurrence in the songbird trade cannot be ruled (especially owing to the fact out-of-range Zosterops in markets are notoriously difficult to identify), this species has not been recorded in market surveys (S. Bruslund in litt. 2023) and, in absence of evidence to the contrary, trapping is not thought to be causing declines. In the absence of other threats, the population is considered stable.

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

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Shrubland	Subtropical/Tropical Moist	major	resident
Altitude	0 - 90 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		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%)		Negligible declines		Low Impact: 5
		Stresses Ecosystem degradation
Natural system modifications	Fire & fire suppression - Increase in fire frequency/intensity	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation

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Recommended citation
BirdLife International (2024) Species factsheet: Kai Besar White-eye Zosterops grayi. Downloaded from https://datazone.birdlife.org/species/factsheet/kai-besar-white-eye-zosterops-grayi on 22/11/2024.
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 22/11/2024.