Data Zone
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 is extremely 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 global population is estimated to number 8,100,000 mature individuals (Partners in Flight 2020).
Trend justification
The species has been undergoing a moderate decline between 1970 and 2017, at an average rate of 12% over ten years (Partners in Flight 2019; Rosenberg et al. 2019).
Text account compilers
Hermes, C.
Contributors
Ekstrom, J. & Butchart, S.
Recommended citation
BirdLife International (2024) Species factsheet: Willow Flycatcher Empidonax traillii. Downloaded from
https://datazone.birdlife.org/species/factsheet/willow-flycatcher-empidonax-traillii on 22/12/2024.
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 22/12/2024.