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 appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size may be moderately small to large, 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 is suspected to number fewer than 50,000 mature individuals (Partners in Flight 2022); thus it is here placed in the band 20,000-49,999 mature individuals. The species is described as 'common' (Stotz et al. 1996).
Trend justification
The population trend has not been investigated. Forest loss within the range has been negligible (<1% over ten years; Global Forest Watch 2021, using Hansen et al. [2013] data and methods disclosed therein), the species is able to tolerate considerable levels of habitat degradation and disturbance (Sánchez-M. 2020), and it is commonly observed (eBird 2022). Therefore, in the absence of evidence for any declines or substantial threats, the species is suspected of being stable.
Text account compilers
Hermes, C.
Contributors
Butchart, S. & Ekstrom, J.
Recommended citation
BirdLife International (2024) Species factsheet: Black-billed Nightingale-thrush Catharus gracilirostris. Downloaded from
https://datazone.birdlife.org/species/factsheet/black-billed-nightingale-thrush-catharus-gracilirostris on 23/11/2024.
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 23/11/2024.