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). The population trend appears to be increasing, 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 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.
This species has undergone a large and statistically significant increase over the last 40 years in North America (86.7% increase over 40 years, equating to a 16.8% increase per decade; data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007).
Text account compilers
Ekstrom, J., Butchart, S.
BirdLife International (2023) Species factsheet: Strix varia. Downloaded from http://www.birdlife.org on 31/03/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 31/03/2023.