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Montana Field Guides

Barred Owl - Strix varia

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Native Species

Global Rank: G5
State Rank: S4
(see State Rank Reason below)


Agency Status
USFWS: MBTA
USFS:
BLM:
PIF:


 

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Copyright by Borror Laboratory of Bioacoustics, Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, OH, all rights reserved.
State Rank Reason (see State Rank above)
Species is apparently secure and not at risk of extirpation or facing significant threats in all or most of its range.
  • Details on Status Ranking and Review
    Barred Owl (Strix varia) Conservation Status Review
    Review Date = 12/22/2011
    Population Size

    ScoreU - Unknown

    CommentUnknown.

    Range Extent

    ScoreF - 20,000-200,000 km squared (about 8,000-80,000 square miles)

    Comment114113 square kilometers based on Natural Heritage Program range maps

    Long-term Trend

    ScoreF - Increase (increase of >25%)

    CommentSpecies is known to have been expanding its range throughout the 20th century.

    Short-term Trend

    ScoreU/E - Unknown, but believed to be stable with population, range, area occupied, and/or number or condition of occurrences unchanged or remaining within ±10% fluctuation

    CommentNo trend data available, but likely stable within +/- 10% over the last 10 years.

    Threats

    ScoreB - Moderate and imminent threat. Threat is moderate to severe and imminent for a significant proportion (20-60%) of the population or area.

    CommentFire, disease, and timber harvest probably represent the greatest threats to the species since it is dependent on mature or old growth forest.

    SeverityModerate - Major reduction of species population or long-term degradation or reduction of habitat in Montana, requiring 50-100 years for recovery.

    CommentMature forests require more than 50 years to regenerate after fire, disease, or timber harvest.

    ScopeModerate - 20-60% of total population or area affected

    Comment>20% of mature forests in western Montana are being impacted or threatened by disease, fire, or timber harvest.

    ImmediacyModerate - Threat is likely to be operational within 2-5 years.

    CommentOngoing

    Intrinsic Vulnerability

    ScoreB - Moderately Vulnerable. Species exhibits moderate age of maturity, frequency of reproduction, and/or fecundity such that populations generally tend to recover from decreases in abundance over a period of several years (on the order of 5-20 years or 2-5 generations); or species has moderate dispersal capability such that extirpated populations generally become reestablished through natural recolonization (unaided by humans).

    Environmental Specificity

    ScoreB - Narrow. Specialist. Specific habitat(s) or other abiotic and/or biotic factors (see above) are used or required by the Element, but these key requirements are common and within the generalized range of the species within the area of interest.

    CommentAssociated with mature and old growth conifer forest.

 
General Description
Round-headed, eyes brown, bill yellow. Facial disk whitish/brown with dark brown trim. Ventrally, a short bib across neck and upper chest, marked with horizontal brown barring. Chest, sides, and belly vertically streaked with dark brown on white. Dorsally, mottled brown and white. SIZE: 19 to 21 inches. WEIGHT: 22 to 29 ounces (one to two pounds). Call is "Who, who, who-whoo" usually given at least twice. Loud and resounding.

For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.

Diagnostic Characteristics
Great Gray Owl has yellow eyes, is larger, has a long tail, and is gray.

Species Range
Montana Range Range Descriptions

Year-round
 


Observations in Montana Natural Heritage Program Database
Number of Observations: 932

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density

Recency

SUMMER (Feb 16 - Dec 14)
Direct Evidence of Breeding

Indirect Evidence of Breeding

No Evidence of Breeding

WINTER (Dec 15 - Feb 15)
Regularly Observed

Not Regularly Observed


 

(Observations spanning multiple months or years are excluded from time charts)



Migration
Probably year-round resident.

Habitat
Restricted to forested areas, ranging from swamps and riparian areas to upland regions. Large, unfragmented blocks of forests preferred. Throughout its range, found in association with mature and old growth forests, typically of mixed deciduous-coniferous composition (Mazur and James 2000).

Ecological Systems Associated with this Species
  • Details on Creation and Suggested Uses and Limitations
    How Associations Were Made
    We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
    1. Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2012, Adams 2003, and Werner et al. 2004);
    2. Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;
    3. Examining the observation records for each species in the state-wide point observation database associated with each ecological system;
    4. Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".
    Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.  In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.  However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if point observations were associated with that system.  Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.  The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.  If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.

    Suggested Uses and Limitations
    Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.  These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: mtnhp.org/requests) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.  Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.  Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.  Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).  Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.

    Literature Cited
    • Adams, R.A.  2003.  Bats of the Rocky Mountain West; natural history, ecology, and conservation.  Boulder, CO: University Press of Colorado.  289 p.
    • Dobkin, D. S.  1992.  Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34.  Missoula, MT.
    • Foresman, K.R.  2012.  Mammals of Montana.  Second edition.  Mountain Press Publishing, Missoula, Montana.  429 pp.
    • Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998.  Montana atlas of terrestrial vertebrates.  Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT.  1302 p.
    • Hutto, R.L. and J.S. Young.  1999.  Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32.  72 p.
    • Maxell, B.A.  2000.  Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species.  Report to U.S. Forest Service Region 1.  Missoula, MT: Wildlife Biology Program, University of Montana.  161 p.
    • Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath.  2004.  Amphibians and reptiles of Montana.  Missoula, MT: Mountain Press Publishing Company. 262 p.

Food Habits
An opportunistic predator, consuming small mammals and rabbits, birds up to the size of grouse, amphibians, reptiles, and invertebrates (Mazur and James 2000).

Reproductive Characteristics
Begins nesting March to April. Nests in broken-topped snags, natural cavities, and old stick nests built by other birds. Clutch size two to four. Incubation approximately 30 days. Young fledge at 35 to 40 days.


References
  • Literature Cited AboveLegend:   View Online Publication
    • Marks, J.S., P. Hendricks, and D. Casey. 2016. Birds of Montana. Arrington, VA. Buteo Books. 659 pages.
    • Mazur, K. M., and P. C. James. 2000. Barred Owl (Strix varia). In The birds of North America, No. 508 (A. Poole and F. Gill, Eds.). Academy of Natural Sciences of Philadelphia and American Ornithologists’ Union.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Allen, A. W. 1987. Habitat suitability index models: Barred Owl. U.S. Fish Wildl. Serv. Biol. Rep. 82(10.143). 17 pp.
    • American Ornithologists’ Union [AOU]. 1998. Check-list of North American birds, 7th edition. American Ornithologists’ Union, Washington, D.C. 829 p.
    • Boxall, P.C. and P.H.R. Stepney. 1982. The distribution and status of the Barred Owl in Alberta. Can. Field-Nat. 96:46-50.
    • Brelsford, M. 1992. Boreal owl (Aegolius funereus) and flammulated owl (Otus flammeolus) survey results for the Livingston district of the Gallatin National Forest. Unpublished report to the Gallatin National Forest by the Montana Natural Heritage Program, Helena, MT. 22 pp.
    • Call, M.W. 1979. Habitat management guides for birds of prey. Technical Note 338. Denver, CO: USDI Bureau of Land Management. 70 p.
    • Carlson, J. 1991. Results of boreal owl surveys on the Jefferson Division of the Lewis & Clark National Forest. Montana Natural Heritage Program, Helena, MT. 33 pp.
    • Dunbar, D. L., B.P. Booth, E.D. Forsman, A.E. Hetherington, and D.J. Wilson. 1991. Status of the Spotted Owl, Strix occidentalis, and Barred Owl, Strix varia, in southwestern British Columbia. Can. Field-Nat. 105:464-468.
    • Ehrlich, P., D. Dobkin, and D. Wheye. 1988. The birder’s handbook: a field guide to the natural history of North American birds. Simon and Schuster Inc. New York. 785 pp.
    • Ellis, D. H., D. W. Smith, and P. L. Wright. 1987. Barred Owl specimen records for Montana. Western Birds 18:217-218.
    • Hays, R., R.L. Eng, and C.V. Davis (preparers). 1984. A list of Montana birds. Helena, MT: MT Dept. of Fish, Wildlife & Parks.
    • Hejl, S.J. and L.C. Paige. 1994. A preliminary assessment of birds in continuous and fragmented forests of western red cedar/western hemlock in northern Idaho. In: Proceedings of interior cedar-hemlock-white pine forests: ecology and management. p. 189-197 Department of Natural Resource Sciences, Pullman, WA: Washington State University.
    • Hejl, S.J., R.L. Hutto, C.R. Preston, and D.M. Finch. 1995. The effects of silvicultural treatments on forest birds in the Rocky Mountains. pp. 220-244 In: T.E. Martin and D.M. Finch (eds). Ecology and Management of Neotropical Migratory Birds. New York, NY: Oxford Univ. Press. 489 p.
    • Holt, D. W., and J. M. Hillis. 1987. Current status and habitat associations of forest owls in western Montana. Pages 281-288 in Biology and conservation of northern forest owls: Symposium proceedings (R. W. Nero, R. J. Clark, R. J. Knapton, and R. H. Hamre, Eds.). U.S. Forest Service General Technical Report RM-142, Fort Collins, Colorado.
    • Holt, D. W., R. Domenech, and A. Paulson. 2001. Status and distribution of the Barred Owl in Montana. Northwestern Naturalist 82:102-110.
    • Johnsgard, P.A. 1992. Birds of the Rocky Mountains with particular reference to national parks in the northern Rocky Mountain region. Lincoln: University of Nebraska Press. xi + 504 pp.
    • Joslin, Gayle, and Heidi B. Youmans. 1999. Effects of recreation on Rocky Mountain wildlife: a review for Montana. [Montana]: Montana Chapter of the Wildlife Society.
    • Leder, J.E. and M.L. Walters. 1980. Nesting observations for the Barred Owl in western Washington. Murrelet 61(3):110-112.
    • Lenard, S., J. Carlson, J. Ellis, C. Jones, and C. Tilly. 2003. P. D. Skaar's Montana bird distribution, 6th edition. Montana Audubon, Helena, MT. 144 pp.
    • Marks, J.S., D.P. Hendricks, and V.S. Marks. 1984. Winter food habits of Barred Owls in western Montana. Murrelet 65:27-28.
    • Montana Bird Distribution Committee. 2012. P.D. Skaar's Montana bird distribution. 7th Edition. Montana Audubon, Helena, Montana. 208 pp. + foldout map.
    • Mosher, B.A. 2011. Avian community response to a mountain beetle epidemic. M.Sc. Thesis. Bozeman, MT: Montana State University. 55 p.
    • MT Fish, Wildlife & Parks. No date. Blackfoot-Clearwater Wildlife Management Area checklist.
    • Nicholls, T. H. and D. W. Warner. 1972. Barred Owl habitat use as determined by radiotelemetry. J. Wildl. Manage. 36: 213-224.
    • Oechsli, L.M. 2000. Ex-urban development in the Rocky Mountain West: consequences for native vegetation, wildlife diversity, and land-use planning in Big Sky, Montana. M.Sc. Thesis. Montana State University, Bozeman. 73 p.
    • Shea, D. S. 1974. Barred Owl records in western Montana. Condor 76:222.
    • Sibley, D. 2014. The Sibley guide to birds. Alfred A. Knopf, New York, NY. 598 pp.
    • Skaar, P. D., D. L. Flath, and L. S. Thompson. 1985. Montana bird distribution. Montana Academy of Sciences Monograph 3(44): ii-69.
    • Skaar, P.D. 1969. Birds of the Bozeman latilong: a compilation of data concerning the birds which occur between 45 and 46 N. latitude and 111 and 112 W. longitude, with current lists for Idaho, Montana, Wyoming, impinging Montana counties and Yellowstone National Park. Bozeman, MT. 132 p.
    • Swan River National Wildlife Refuge. 1982. Birds of the Swan River NWR. Kalispell, MT: NW MT Fish and Wildlife Center pamphlet.
    • Taylor, A.L. Jr. and E.D. Forsman. 1976. Recent range extensions of the Barred Owl in western North America, including the first records for Oregon. Condor 78(4):560-561.
    • Taylor, D.M. and C.H. Trost. 1987. The status of historically rare of unrecorded birds in Idaho. Unpublished manuscript. 68 p.
    • Thompson, Richard W., Western Resource Dev. Corp., Boulder, CO., 1996, Wildlife baseline report for the Montana [Montanore] Project, Lincoln and Sanders counties, Montana. In Application for a Hard Rock Operating Permit and Proposed Plan of Operation, Montanore Project, Lincoln and Sanders Counties, Montana. Vol. 5. Stroiazzo, John. Noranda Minerals Corp., Libby, MT. Revised September 1996.
    • U.S. Forest Service. 1991. Forest and rangeland birds of the United States: Natural history and habitat use. U.S. Department of Agriculture, Forest Service Agricultural Handbook 688. 625 pages.
    • Watts, C.R. and L.C. Eichhorn. 1981. Changes in the birds of central Montana. Proceedings of the Montana Academy of Sciences 40:31-40.
    • Wright, P.L. 1976. Further bird records from western Montana. Condor 78:418-420.
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Citation for data on this website:
Barred Owl — Strix varia.  Montana Field Guide.  .  Retrieved on , from