Justification of Red List Category
This species has an extremely large range, and hence does not 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.
The global population size has not been quantified, but the species is described as generally uncommon, although common in the Amur and Ussuri river valleys and common during its non-breeding season in South-East Asia and the Indian Subcontinent (del Hoyo et al. 2006). National population sizes have been estimated at < c.1,000 individuals on migration in Korea and c.100-10,000 breeding pairs and c.50-1,000 individuals on migration in Russia (Brazil 2009).
The population is suspected to be in decline owing to ongoing habitat destruction.
Text account compilers
Ekstrom, J., Butchart, S.
BirdLife International (2023) Species factsheet: Arundinax aedon. Downloaded from http://datazone.birdlife.org/species/factsheet/thick-billed-warbler-arundinax-aedon on 29/05/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://datazone.birdlife.org on 29/05/2023.