Justification of Red List category
Although this species may have a small range, it is not believed to approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Population justification
The population was estimated at 556,000 individuals in 1967 (del Hoyo et al. 2008), roughly equivalent to 370,000 mature individuals. Due to the age of this estimate we place the population in the broad band 100,000-499,999 mature individuals here.
Trend justification
The population trend is difficult to determine because of uncertainty over the impacts of habitat modification on population sizes.
Text account compilers
Butchart, S., Ekstrom, J. & Khwaja, N.
Recommended citation
BirdLife International (2025) Species factsheet: Reunion Grey White-eye Zosterops borbonicus. Downloaded from
https://datazone.birdlife.org/species/factsheet/reunion-grey-white-eye-zosterops-borbonicus on 10/01/2025.
Recommended citation for factsheets for more than one species: BirdLife International (2025) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 10/01/2025.