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 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.
The global population is estimated to number approximately 200,000 individuals which equates to 133,000 mature individuals (Partners in Flight Science Committee 2013). The North American population is estimated at 100,000 individuals (Partners in Flight Science Committee 2013). The European population is estimated at 700-2,300 pairs, which equates to 1,400-4,600 mature individuals (BirdLife International 2015).
This species has undergone a small or statistically insignificant decrease over the last 40 years in North America (data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007). In Europe the population size is estimated to be fluctuating (BirdLife International 2015).
Harvesting of species for food, feathers and claws by native peoples may have local impact on population, but unlikely to have any wider effect on total numbers. Electrocution, airplane strikes, collision with vehicles and entanglement in fishing equipment have all been identified as sources of mortality in Alberta, Canada (Holt et al. 2015). Climate change has a significant impact on the onset of spring and snowmelt in the breeding areas which may change the availability of prey for the species (International Snowy Owl Working Group 2010).
Text account compilers
Ekstrom, J., Butchart, S. & Ashpole, J
BirdLife International (2017) Species factsheet: Bubo scandiacus. Downloaded from http://www.birdlife.org on 20/10/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 20/10/2017.