Surnia ulula 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Strigiformes Strigidae

Scientific Name: Surnia ulula
Species Authority: (Linnaeus, 1758)
Regional Assessments:
Common Name(s):
English Northern Hawk-owl, Hawk Owl, Northern Hawk-Owl
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. Lynx Edicions BirdLife International.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2015
Date Assessed: 2012-05-03
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Facilitator/Compiler(s): Ekstrom, J., Butchart, S. & 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:
2012 Least Concern (LC)
2009 Least Concern (LC)
2008 Least Concern (LC)
2004 Least Concern (LC)
2000 Lower Risk/least concern (LR/lc)
1994 Lower Risk/least concern (LR/lc)
1988 Lower Risk/least concern (LR/lc)

Geographic Range [top]

Countries occurrence:
Canada; China; Estonia; Finland; Kazakhstan; Korea, Democratic People's Republic of; Kyrgyzstan; Mongolia; Norway; Russian Federation; Sweden; United States
Regionally extinct:
Austria; Belarus; Belgium; Bermuda; Czech Republic; Denmark; Faroe Islands; France; Germany; Hungary; Japan; Luxembourg; Montenegro; Netherlands; Poland; Romania; Serbia (Serbia); Slovakia; Spain; Switzerland; Ukraine; United Kingdom
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 21100000
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Continuing decline in number of locations: Unknown
Extreme fluctuations in the number of locations: No
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The global population is estimated to number > c.120,000 individuals which equates to 80,000 mature individuals (Partners in Flight Science Committee 2013). The North American population is estimated at approximately 60,000 individuals which equates to 40,000 mature individuals (Partners in Flight Science Committee 2013). The European population is estimated at 10,400-53,900 pairs, which equates to 20,800-108,000 mature individuals (BirdLife International 2015). Europe forms approximately 13% of the global range, so a very preliminary estimate of the global population size is 160,000-831,000 mature individuals, although further validation of this estimate is needed. The population is precautionarily placed in the band 100,000-499,999 mature individuals however the actual population could be larger.

Trend Justification:  The overall trend is likely to be fluctuating. This species has undergone a small or statistically insignificant increase over the last 40 years in North America (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 trend is unknown (BirdLife International 2015).
Current Population Trend: Stable
Additional data:
Number of mature individuals: 100000-499999 Continuing decline of mature individuals: Unknown
Extreme fluctuations: No Population severely fragmented: No
Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No

Habitat and Ecology [top]

Threats [top]

Major Threat(s): The species is dependent on rodent populations and numbers fluctuate with the abundance of small rodents. In Finland, the population has declined since 19th century, as a result of disappearance of hollow trees and through human persecution (Holt et al. 2013). In North America, forestry practices and fire suppression may reduce suitable habitat (Holt et al. 2013). The species is known to be vulnerable to West Nile Virus (Komar 2003).

Citation: BirdLife International. 2015. Surnia ulula. The IUCN Red List of Threatened Species 2015: e.T22689189A80510941. . Downloaded on 25 November 2015.
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