Strix aluco 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Strigiformes Strigidae

Scientific Name: Strix aluco Linnaeus, 1758
Regional Assessments:
Common Name(s):
English Tawny 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. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
Taxonomic Notes: Strix aluco and S. nivicolum (del Hoyo and Collar 2014) were previously lumped as S. aluco following Sibley and Monroe (1990, 1993).

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2016
Date Assessed: 2016-10-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Facilitator/Compiler(s): Butchart, S., Ekstrom, J., Symes, A., Taylor, 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 stable, 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 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.
Previously published Red List assessments:

Geographic Range [top]

Countries occurrence:
Afghanistan; Albania; Algeria; Andorra; Armenia; Austria; Azerbaijan; Belarus; Belgium; Bosnia and Herzegovina; Bulgaria; China; Croatia; Czech Republic; Denmark; Estonia; Finland; France; Georgia; Germany; Greece; Hungary; Iran, Islamic Republic of; Iraq; Israel; Italy; Jordan; Kazakhstan; Kyrgyzstan; Latvia; Lebanon; Liechtenstein; Lithuania; Luxembourg; Macedonia, the former Yugoslav Republic of; Moldova; Montenegro; Morocco; Netherlands; Norway; Pakistan; Palestinian Territory, Occupied; Poland; Portugal; Romania; Russian Federation (Central Asian Russia, European Russia); Serbia; Slovakia; Slovenia; Spain; Sweden; Switzerland; Syrian Arab Republic; Tajikistan; Tunisia; Turkey; Turkmenistan; Ukraine; United Kingdom; Uzbekistan
Additional data:
Continuing decline in area of occupancy (AOO):Unknown
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:23300000
Continuing decline in extent of occurrence (EOO):UnknownExtreme fluctuations in extent of occurrence (EOO):No
Continuing decline in number of locations:Unknown
Extreme fluctuations in the number of locations:No
Upper elevation limit (metres):2350
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:In Europe, the breeding population is estimated to number 535,000-939,000 pairs, which equates to 1,070,000-1,880,000 mature individuals (BirdLife International 2015). Europe forms c. 80% of the global range, so a very preliminary estimate of the global population size is 1,400,000-2,400,000 mature individuals, although further validation of this estimate is needed. The population is therefore placed in the band 1,000,000-2,999,999 mature individuals.

Trend Justification:  The population is suspected to be stable in the absence of evidence for any declines or substantial threats. The European population trend is unknown (BirdLife International 2015).
Current Population Trend:Stable
Additional data:
Number of mature individuals:1000000-2999999Continuing decline of mature individuals:Unknown
Extreme fluctuations:NoPopulation severely fragmented:No
Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:The primary habitat of this species is broad-leaved forest, however it adapts well to man-made and altered habitats. It is found in urban areas, clear-felled areas and intensive agricultures. In woodland habitats it inhabits mixed conifer and broad-leaved forests, sub-alpine conifer forest and conifer plantations (Hagemeijer and Blair 1997). It is monogamous and pairs for life, although is occasionally bigamous. The breeding season is from February to July (Holt et al. 1999). It nests in holes in trees, cliffs, buildings and steep river banks. Also often uses, nestboxes, the old nests of large birds, burrows of large mammals (König 2008), dreys of squirrels (Sciurus) (Holt et al. 1999) and shallow depressions on the ground at the base of a tree or beneath a bush. Typically it lays three to five eggs (König 2008). It feeds on small mammals and small birds and will also consume amphibians, reptiles, earthworms, snails, beetles and other insects and occasionally fish (Holt et al. 1999). The species is sedentary and highly territorial (Hagemeijer and Blair 1997).
Continuing decline in area, extent and/or quality of habitat:Unknown
Generation Length (years):8
Movement patterns:Not a Migrant

Threats [top]

Major Threat(s): In Britain, human persecution drove declines during the 19th century (Holt et al. 1999). The species is reliant on prey availability, which is often determined by woodland structure. In the north, competition with the Ural Owl (Strix uralensis) may limit the expansion of its range (Hagemeijer and Blair 1997). Locally, pesticide use, traffic and electrocution from powerlines also threaten this species (König 2008).

Conservation Actions [top]

Conservation Actions:

Conservation Actions Underway

CITES Appendix II. Bern Convention Appendix II. There are currently no known, specific conservation measures for this species. 

Conservation Actions Proposed

Further research on aspects of this species’s biology is recommended (König 2008).

Citation: BirdLife International. 2016. Strix aluco. The IUCN Red List of Threatened Species 2016: e.T22725469A86871093. . Downloaded on 25 May 2018.
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