NT
Biak White-eye Zosterops mysorensis



Taxonomy

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.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2023 Near Threatened B1b(iii)
2016 Near Threatened C1+2a(i)
2012 Near Threatened C1+2a(i)
2008 Near Threatened C1; C2a(i)
2004 Near Threatened
2000 Lower Risk/Near Threatened
1994 Lower Risk/Near Threatened
1988 Lower Risk/Least Concern
Species attributes

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

Estimate Data quality
Extent of Occurrence (breeding/resident) 3,600 km2 medium
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size unknown - - -
Population trend decreasing poor suspected 2016-2026
Rate of change over the past 10 years/3 generations (longer of the two periods) 1-9% - - -
Rate of change over the future 10 years/3 generations (longer of the two periods) 1-9% - - -
Rate of change over the past & future 10 years/3 generations (longer of the two periods) 1-9% - - -
Generation length 2.55 years - - -
Number of subpopulations 1 - - -
Percentage of mature individuals in largest subpopulation 100% - - -

Population justification: This is a poorly known species and no population estimates are available. It is described as 'uncommon' by Beehler and Pratt (2016) but appears to be widespread and readily observed in small flocks (eBird 2022). The population size is not thought to be below 10,000 mature individuals (the threshold for listing as Threatened under Criterion C).

Trend justification: No direct assessment of rate of population change has been made for the species. It is considered to be relatively forest dependent (although it is somewhat tolerant of degraded habitat) and there has been a slow rate of forest cover loss, up to 4% in the ten years to 2022 (data from Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein) and this is suspected to be causing broadly equivalent reductions in population size of this species. These rates are suspected to occur in the future. An accelerated rate of decline is considered unlikely given the impenetrability of Supiori's forests.


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
Altitude 0 - 675 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%) 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 Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation

Recommended citation
BirdLife International (2024) Species factsheet: Biak White-eye Zosterops mysorensis. Downloaded from https://datazone.birdlife.org/species/factsheet/biak-white-eye-zosterops-mysorensis 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.