Zosterops hypolais 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Passeriformes Zosteropidae

Scientific Name: Zosterops hypolais
Species Authority: Hartlaub & Finsch, 1872
Common Name(s):
English Plain White-eye

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Facilitator/Compiler(s): Derhé, M., Mahood, S., O'Brien, A., Shutes, S.
This species has an extremely small range on one small group of islands where it is currently common. The range is not yet severely fragmented or restricted to few locations. For these reasons, the species is classified as Near Threatened. However, it could decline rapidly if alien predators such as brown tree snake Boiga irregularis were introduced, and would then warrant uplisting to a higher threat category.

Previously published Red List assessments:
2008 Near Threatened (NT)
2004 Near Threatened (NT)
2000 Lower Risk/near threatened (LR/nt)
1994 Lower Risk/near threatened (LR/nt)
1988 Lower Risk/least concern (LR/lc)

Geographic Range [top]

Range Description: Zosterops hypolais is endemic to the four islands of Yap, Federated States of Micronesia, where it is common, and, in 1984, was estimated to have a population of 86,864 individuals (Engbring et al. 1990).

Countries occurrence:
Micronesia, Federated States of
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 100
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Continuing decline in number of locations: Unknown
Extreme fluctuations in the number of locations: No
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Engbring et al. (1990) estimated the population to number 86,864 individuals, which is rounded to 86,900 individuals here.

Trend Justification:  There are no data on trends; however, the species is thought to be common and tolerates a wide range of habitats, therefore the population is currently thought to be stable.
Current Population Trend: Stable
Additional data:
Continuing decline of mature individuals: No
Extreme fluctuations: No Population severely fragmented: No
Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No
No. of individuals in largest subpopulation: 100

Habitat and Ecology [top]

Habitat and Ecology: It is found in nearly all forest and vegetation types, including brushy thickets in open savannas and meadows.

Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Unknown
Generation Length (years): 3.5
Movement patterns: Not a Migrant

Threats [top]

Major Threat(s): It appears to be in no particular danger but, given its small range, it will always be at some risk from stochastic events, including exotic introductions such as the brown tree snake Boiga irregularis, which has caused the extirpation and extinction of birds on Guam (to USA) (Engbring et al. 1990).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
None is known.

Conservation Actions Proposed
Periodically monitor populations to establish trends. Take measures to ensure B. irregularis never reaches Yap.

Citation: BirdLife International. 2012. Zosterops hypolais. The IUCN Red List of Threatened Species 2012: e.T22714053A39628917. . Downloaded on 24 May 2016.
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