|Scientific Name:||Strix nebulosa Forster, 1772|
|Taxonomic Source(s):||del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer(s):||Butchart, S. & Symes, A.|
|Facilitator/Compiler(s):||Butchart, S., Ekstrom, J. & Ashpole, J|
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 fluctuating, 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.
|Previously published Red List assessments:|
Native:Belarus; Canada; China; Finland; Kazakhstan; Lithuania; Mongolia; Norway; Russian Federation (Central Asian Russia, Eastern Asian Russia, European Russia); Sweden; Ukraine; United States
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The global population is estimated to number approximately 190,000 individuals which equates to 127,000 mature individuals (Partners in Flight Science Committee 2013). The North American population is estimated at 90,000 individuals or 60,000 mature individuals (Partners in Flight Science Committee 2013). The European population is estimated at 1,900-7,500 pairs, which equates to 3,900-15,000 mature individuals (BirdLife International 2015). Europe forms approximately 13% of the global range, so a very preliminary estimate of the global population size is 30,000-115,000 mature individuals, although further validation of this estimate is needed. The population is precautionarily placed in the band 50,000-99,999 mature individuals but the actual population could be considerably larger.|
Trend Justification: The overall trend is likely to be increasing. This species has undergone a large and statistically significant increase over the last 40 years in North America (4900% increase over 40 years, equating to a 166% increase per decade; data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007). Note, however, that these surveys cover less than 50% of the species's range in North America. In Europe the population size is also estimated to be increasing (BirdLife International 2015).
|Current Population Trend:||Increasing|
|Major Threat(s):||The species is affected by global warming, which if it persists will continue to move the species’s range northwards (Hagemeijer and Blair 1997). Populations fluctuate in line with vole numbers (Cornulier et al. 2013). Locally, hunting may still be a threat (König 2008). It is also vulnerable to road traffic collisions and loss of habitat from forestry (Holt et al. 1999). Collisions with power lines and cables are also a threat. In North America timber harvesting, collisions with vehicles, strychnine poisoning of pocket gophers, disturbance at foraging habitats due to development of campsites, grazing, peat extraction and agriculture have all been identified as potential threats (Holt et al. 1999). The species is known to be vulnerable to West Nile Virus (Lopes et al. 2007).|
BirdLife International. 2015. European Red List of Birds. Office for Official Publications of the European Communities, Luxembourg.
Cornulier, T., Yoccoz, N.G., Bretagnolle, V., Brommer, J.E., Butet, A., Ecke, F., Elston, D.A., Framstad, E., Henttonen, H., Hörnfeldt, B., Huitu, O., Imholt, C., Ims, R.A., Jacob, J., Jędrzejewska, B., Millon, A., Petty, S.J., Pietiäinen, H., Tkaadlec, E., Zub, K. and Lambin, X. 2013. Europe-wide dampening of population cycles in keystone herbivores. Science 340(6128): 63-66.
Hagemeijer, E.J.M. and Blair, M.J. 1997. The EBCC atlas of European breeding birds: their distribution and abundance. T. and A. D. Poyser, London.
Holt, D.W., Berkley, R., Deppe, C., Enríquez Rocha, P., Petersen, J.L., Rangel Salazar, J.L., Segars, K.P. and Wood, K.L. 1999. Great Grey Owl (Strix nebulosa). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. and de Juana, E. (eds), Handbook of the Birds of the World Alive, Lynx Edicions, Barcelona.
IUCN. 2016. The IUCN Red List of Threatened Species. Version 2016-3. Available at: www.iucnredlist.org. (Accessed: 07 December 2016).
König, C. and Weick, F. 2008. Owls of the World. Christopher Helm, London.
Lopes, H., Redig, P., Glaser, A., Armien, A. and Wünschmann, A. 2007. Clinical Findings, Lesions, and Viral Antigen Distribution in Great Gray Owls (Strix nebulosa) and Barred Owls (Strix varia) with Spontaneous West Nile Virus Infection. Avian Diseases 51(1): 140-145.
Partners in Flight Science Committee. 2013. Population Estimates Database, version 2013. Available at: http://rmbo.org/pifpopestimates. (Accessed: 09/07/2015).
|Citation:||BirdLife International. 2016. Strix nebulosa. The IUCN Red List of Threatened Species 2016: e.T22689118A93218931.Downloaded on 18 November 2017.|
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