Data Zone
Justification of Red List category
This species has a moderately small range, being restricted to four very small islands. The population is currently considered stable; however, the accidental introduction of predators such as Brown Tree Snake Boiga irregularis could plausibly cause the species to qualify for a higher threat category within a very short time period. It is therefore assessed as Near Threatened.
Population justification
Within its small range it is considered common and widespread, with 2-15 individuals found in every c.100 m stretch of forest edge (van Balen 2020). Engbring et al. (1990) estimated the population to number 86,864 individuals, roughly equating to 60,000 mature individuals and placed here in the range 40,000-80,000 mature individuals. Although there is no more recent population estimate or trend assessment, Yap Plain White-eye remains among the most commonly encountered avian species on Yap (Robertson and Robertson 2016).
Trend justification
Most species surveyed on Yap in 2004 appeared to be less abundant than in Engbring et al.'s (1990) surveys (Robertson and Robertson 2016). The reasons for this are uncertain but could be attributed to Typhoon Sudal in 2004, difference in survey methods or changes in habitat availability (Robertson and Robertson 2016). However, there has been no recent trend assessment; the species is thought to be common and it tolerates a wide range of habitats. Currently the population is suspected to be stable in the absence of any recent evidence for any declines or substantial threats.
Zosterops hypolais is endemic to the four islands of Yap, Federated States of Micronesia, where it is common.
It is found in nearly all forest and vegetation types, including brushy thickets in open savannas and meadows. It is common along line transects in mangroves, savannah and forest (Robertson and Robertson 2016).
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 (Engbring et al. 1990).
Conservation Actions Underway
None is known.
Text account compilers
Vine, J.
Contributors
Derhé, M., Mahood, S., O'Brien, A. & Shutes, S.
Recommended citation
BirdLife International (2024) Species factsheet: Yap Plain White-eye Zosterops hypolais. Downloaded from
https://datazone.birdlife.org/species/factsheet/yap-plain-white-eye-zosterops-hypolais 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.