LC
Kai Besar White-eye Zosterops grayi



Taxonomy

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.

IUCN Red List criteria met and history
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
Species attributes

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

Estimate Data quality
Extent of Occurrence (breeding/resident) 880 km2 medium
Area of Occupancy (breeding/resident) 820 km2
Severely fragmented? no -
Population
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 distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Indonesia extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name

Habitats & altitude
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  

Threats & impact
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

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 25/12/2024.
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 25/12/2024.