email a friend
printable version
LC
Northern Long-eared Owl Asio otus
BirdLife is updating this factsheet for the 2016 Red List
Please email us with any relevant information

Justification
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.

Taxonomic source(s)
AERC TAC. 2003. AERC TAC Checklist of bird taxa occurring in Western Palearctic region, 15th Draft. Available at: #http://www.aerc.eu/DOCS/Bird_taxa_of _the_WP15.xls#.
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

Taxonomic note
Asio otus and A. abyssinicus (Sibley and Monroe 1990, 1993) are retained as separate species contra Cramp (1985) and Dowsett and Forbes-Watson (1993) who include abyssinicus as a subspecies of A. otus.

Population justification
Partners in Flight Science Committee (2013) estimated the global population to number 50,000 individuals. The European population is estimated at 304,000-776,000 pairs, which equates to 609,000-1,550,000 mature individuals (BirdLife International 2015). Europe forms approximately 28% of the global range, so a very preliminary estimate of the global population size is 2,180,000-5,540,000 mature individuals, although further validation of this estimate is needed.

Trend justification
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 trend is unknown (BirdLife International 2015).

Threats
Declines in Britain are thought to be due to the expanding population of Tawny Owl (Strix aluco), competing for space, food and nest sites (Hagemeijer and Blair 1997, Olsen 1999). Agricultural intensification and declining vole populations are also driving declines in Europe (Hagemeijer and Blair 1997, Aschwanden et al. 2005). Locally, threats include pesticide use, persecution and road traffic collisions (König and Weick 2008). Loss of riparian, grassland and other open habitats to development is considered a threat in the U.S.A. (Olsen 1999).

References
Aschwanden, J., Birrer, S. and Jenni, L. 2005. Are ecological compensation areas attractive hunting sites for common kestrels (Falco tinnunculus) and long-eared owls (Asio otus)? Journal of Ornithology 146(3): 279-286.

BirdLife International. 2015. European Red List of Birds. Office for Official Publications of the European Communities, Luxembourg.

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.

IUCN. 2015. The IUCN Red List of Threatened Species. Version 2015-4. Available at: www.iucnredlist.org. (Accessed: 19 November 2015).

König, C. and Weick, F. 2008. Owls of the World. Christopher Helm, London.

Olsen, P.D. 1999. Northern Long-eared Owl (Asio otus). 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.

Partners in Flight Science Committee. 2013. Population Estimates Database, version 2013. Available at: http://rmbo.org/pifpopestimates. (Accessed: 09/07/2015).

Further web sources of information
Detailed species account from Birds in Europe: population estimates trends and conservation status (BirdLife International 2004)

Detailed species account from Birds in Europe: population estimates, trends and conservation status (BirdLife International 2004)

Explore HBW Alive for further information on this species

Search for photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Ekstrom, J., Butchart, S. & Ashpole, J

IUCN Red List evaluators
Butchart, S. & Symes, A.

Recommended citation
BirdLife International (2016) Species factsheet: Asio otus. Downloaded from http://www.birdlife.org on 24/07/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/07/2016.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

ARKive species - Long-eared owl (Asio otus) 0

Key facts
Current IUCN Red List category Least Concern
Family Strigidae (Typical Owls)
Species name author (Linnaeus, 1758)
Population size 2000000-5500000 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 28,400,000 km2
Country endemic? No
Links to further information
- Additional Information on this species
- 2015 European Red List assessment