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Plain White-eye Zosterops hypolais
BirdLife is updating this factsheet for the 2016 Red List
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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.

Taxonomic source(s)
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

Distribution and population
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).

Population justification
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.

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

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 Underway
None is known. Conservation Actions Proposed
Periodically monitor populations to establish trends. Take measures to ensure B. irregularis never reaches Yap.

Engbring, J.; Ramsey, F. L.; Wildman, V. J. 1990. Micronesian forest bird surveys, the Federated States: Pohnpei, Kosrae, Chuuk, and Yap. U.S. Fish and Wildlife Service, Honolulu.

Further web sources of information
Explore HBW Alive for further information on this species

Search for photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Derhé, M., Mahood, S., O'Brien, A., Shutes, S.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2016) Species factsheet: Zosterops hypolais. Downloaded from on 26/10/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from on 26/10/2016.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Key facts
Current IUCN Red List category Near Threatened
Family Zosteropidae (White-eyes)
Species name author Hartlaub & Finsch, 1872
Population size mature individuals
Population trend Stable
Distribution size (breeding/resident) 100 km2
Country endemic? Yes
Links to further information
- Additional Information on this species