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Yap Olive White-eye Zosterops oleagineus

Justification
This species is classified as Near Threatened because it is restricted to one extremely small island where it is thought to have become scarcer in recent years. It would warrant uplisting to a higher threat category if alien predators, such as brown tree-snake Boiga irregularis, were to become established on Yap.

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

Identification
13 cm. Small dark passerine. Mostly olive-green with orange-yellow bill and legs. White eye-ring emphasized by black lores. Similar spp. Plain White-eye Z. hypolais smaller, paler, with less prominent eye-ring. Female and juvenile Micronesian Honeyeater Myzomela rubratra lack greenish tone and eye-ring. Voice Call a grating cheee. Song comprises lively whistled phrases such as fiddle-EE-feedle-DEE repeated monotonously. Hints Moves about in small parties, often in forest edge.

Distribution and population
Zosterops oleagineus is endemic to the four islands of Yap, Federated States of Micronesia. In the 1970s, it could be readily found in any forest area (H. D. Pratt in litt. 1994). In 1984, it was estimated to have a total population of 19,619 individuals and was expected to remain common (Engbring et al. 1990). However, more recently, it appears to have become scarcer (H. D. Pratt in litt. 1994).

Population justification
Engbring et al. (1990) estimated 19,619 individuals, which is rounded to 19,600 individuals here, roughly equivalent to 13,000 mature individuals; it is thought to have become scarcer since.

Trend justification
There are no actual trend data, but D. Pratt in litt (1994) considered the species to have become scarcer in recent years.

Ecology
It is widely distributed in all types of forest and woody vegetation, including mangroves, but shows a preference for better-developed forests (Engbring et al. 1990).

Threats
Loss of habitat from fire is a threat as local people set fire to large areas of savanna during the dry season (B. Raynor in litt. 1995). The species is also at risk from the accidental introduction of alien species, particularly brown tree snake Boiga irregularis which has caused the extinction of many bird species on Guam (to USA) (Engbring et al. 1990).

Conservation Actions Underway
None is known.

Conservation Actions Proposed
Obtain a new population estimate and carry out regular monitoring to determine trends. Educate local people about the effects of dry-season fires on the species. Limit the use of fire in the dry season. Take measures to prevent the introduction of B. irregularis to Yap.

References
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., Stattersfield, A.

Contributors
Pratt, H., Raynor, B.

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

Recommended citation
BirdLife International (2014) Species factsheet: Zosterops oleagineus. Downloaded from http://www.birdlife.org on 23/08/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 23/08/2014.

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 13000 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 100 km2
Country endemic? Yes
Links to further information
- Additional Information on this species