Data Zone
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). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to 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 global population size has not been quantified, but the species is reported to be locally abundant (Heather and Robertson 1997).
Trend justification
Declines have been recorded on two islands, with a corresponding increase where introduced predators are controlled (del Hoyo et al. 2007), suggesting that this is a major threat. Overall, the species is suspected to be in decline.
This species is confined to the forested parts of southern Chatham Island and five smaller offshore islands and islets in the Chatham Island group off the east coast of New Zealand. Subfossils indicate that the range once included several more islands in the group.
Rats Rattus, feral cats and habitat reduction have caused a decline this century on Chatham Island (Heather and Robertson 1997).
12 cm. Small brown and white warbler. Olive brown head and upper parts, darker wings; adult male has white forehead and eyebrow stripe and underparts; female lacks white forehead, underparts are greyish white, and eyebrow, face and throat are yellowish; juvenile like female except upperparts olive grey, underparts yellower and eye brown instead of red. Similar species: None in range. Hints: . Voice: Short, loud song repeated often during breeding season.
Text account compilers
Ekstrom, J., Butchart, S., Harding, M., Fisher, S.
Recommended citation
BirdLife International (2024) Species factsheet: Chatham Islands Gerygone Gerygone albofrontata. Downloaded from
https://datazone.birdlife.org/species/factsheet/chatham-islands-gerygone-gerygone-albofrontata on 26/12/2024.
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 26/12/2024.