Bubo virginianus - (Gmelin, 1788)
Great Horned Owl
Other English Common Names: great horned owl
Other Common Names: Jucurutu, Corujão
Taxonomic Status: Accepted
Related ITIS Name(s): Bubo virginianus (Gmelin, 1788) (TSN 177884)
French Common Names: grand-duc d'Amérique
Spanish Common Names: Buho Cornudo, Ñacurutú
Unique Identifier: ELEMENT_GLOBAL.2.770876
Element Code: ABNSB05010
Informal Taxonomy: Animals, Vertebrates - Birds - Other Birds
 
Kingdom Phylum Class Order Family Genus
Animalia Craniata Aves Strigiformes Strigidae Bubo
Genus Size: C - Small genus (6-20 species)
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Concept Reference
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Concept Reference: Remsen, J. V., Jr., A. Jaramillo, M. Nores, J. F. Pacheco, M. B. Robbins, T. S. Schulenberg, F. G. Stiles, J. M. C. da Silva, D. F. Stotz, and K. J. Zimmer. Version: 21 March 2005. A classification of the bird species of South America. American Ornithologists' Union. Online. Available: http://www.museum.lsu.edu/~Remsen/SACCBaseline.html
Concept Reference Code: N05REM01NAUS
Name Used in Concept Reference: Bubo virginianus
Taxonomic Comments: See McGillivray (1989) for information on geographic variation in size (in North America) and its subspecific taxonomic implications. Dickerman (1991) determined that B. v. occidentalis is a synonym of B. v. subarcticus.
Conservation Status
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NatureServe Status

Global Status: G5
Global Status Last Reviewed: 06Apr2016
Global Status Last Changed: 27Nov1996
Ranking Methodology Used: Ranked by inspection
Rounded Global Status: G5 - Secure
Nation: United States
National Status: N5 (05Jan1997)
Nation: Canada
National Status: N5 (02Jan2018)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Alabama (S5), Alaska (S5), Arizona (S5), Arkansas (S5), California (SNR), Colorado (S5), Connecticut (S5), Delaware (S5), District of Columbia (S2), Florida (SNR), Georgia (S5), Idaho (S5), Illinois (S5), Indiana (S4), Iowa (S5B), Kansas (S5), Kentucky (S4S5), Louisiana (S4), Maine (S5), Maryland (S5), Massachusetts (S5), Michigan (S5), Minnesota (SNR), Mississippi (S5), Missouri (S5), Montana (S5), Navajo Nation (S5), Nebraska (S5), Nevada (S5), New Hampshire (S5), New Jersey (S5B), New Mexico (S5B,S5N), New York (S5), North Carolina (S5), North Dakota (SNR), Ohio (S5), Oklahoma (S5), Oregon (S5), Pennsylvania (S5), Rhode Island (S4B,S4N), South Carolina (S5), South Dakota (S5), Tennessee (S5), Texas (S5B), Utah (S4), Vermont (S3), Virginia (S5), Washington (S5), West Virginia (S4B,S5N), Wisconsin (S5B), Wyoming (S5B,S5N)
Canada Alberta (S5), British Columbia (S5), Labrador (S4), Manitoba (S4), New Brunswick (S4), Newfoundland Island (S4), Northwest Territories (S4?), Nova Scotia (S4), Nunavut (SU), Ontario (S4), Prince Edward Island (S4), Quebec (S5), Saskatchewan (S4), Yukon Territory (S4)

Other Statuses

IUCN Red List Category: LC - Least concern
Convention on International Trade in Endangered Species Protection Status (CITES): Appendix II

NatureServe Global Conservation Status Factors

Range Extent: >2,500,000 square km (greater than 1,000,000 square miles)
Range Extent Comments: BREEDING: western and central Alaska to southern Keewatin and Labrador, south to southern South America. NON-BREEDING: generally throughout breeding range; northernmost populations partially migratory, wintering south to southern Canada and northern U.S.

Population Size Comments: Guesstimated number of breeding pairs in Canada in the early 1990s was 100,000-500,000 (Kirk et al. 1995).

Short-term Trend Comments: Increasing in Canada (Kirk et al. 1995).

Other NatureServe Conservation Status Information

Distribution
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Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDING: western and central Alaska to southern Keewatin and Labrador, south to southern South America. NON-BREEDING: generally throughout breeding range; northernmost populations partially migratory, wintering south to southern Canada and northern U.S.

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map
NOTE: The maps for birds represent the breeding status by state and province. In some jurisdictions, the subnational statuses for common species have not been assessed and the status is shown as not-assessed (SNR). In some jurisdictions, the subnational status refers to the status as a non-breeder; these errors will be corrected in future versions of these maps. A species is not shown in a jurisdiction if it is not known to breed in the jurisdiction or if it occurs only accidentally or casually in the jurisdiction. Thus, the species may occur in a jurisdiction as a seasonal non-breeding resident or as a migratory transient but this will not be indicated on these maps. See other maps on this web site that depict the Western Hemisphere ranges of these species at all seasons of the year.
Endemism: occurs (regularly, as a native taxon) in multiple nations

U.S. & Canada State/Province Distribution
United States AK, AL, AR, AZ, CA, CO, CT, DC, DE, FL, GA, IA, ID, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, MT, NC, ND, NE, NH, NJ, NM, NN, NV, NY, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VA, VT, WA, WI, WV, WY
Canada AB, BC, LB, MB, NB, NF, NS, NT, NU, ON, PE, QC, SK, YT

Range Map
Note: Range depicted for New World only. The scale of the maps may cause narrow coastal ranges or ranges on small islands not to appear. Not all vagrant or small disjunct occurrences are depicted. For migratory birds, some individuals occur outside of the passage migrant range depicted. For information on how to obtain shapefiles of species ranges see our Species Mapping pages at www.natureserve.org/conservation-tools/data-maps-tools.

Range Map Compilers: NatureServe, 2002; WILDSPACETM 2002; WWF-US, 2000


U.S. Distribution by County Help
State County Name (FIPS Code)
NM Dona Ana (35013), Otero (35035)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
13 Tularosa Valley (13050003)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
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Reproduction Comments: Clutch size averages 2-3. Incubation lasts 26-35 days, mostly by female (male supplies food). Young leave nest at 4-5 weeks, fly well at 9-10 weeks, dependent on parents for several weeks. Most yearling females do not nest. Lost clutch may be replaced. Longevity record in the wild is at least 28 years.
Ecology Comments: In Saskatchewan, productivity (number of young per nest and number of breeders) peaked with peak in snowshoe hare population (Houston 1987); declines in hare density resulted in increased owl dispersal and mortality (Houston and Francis 1995). Home range size varies seasonally and geographically. Breeding territories in southwest Yukon ranged from 230-883 hectares, averaging 483 hectares; home ranges of nonterritorial floaters overlapped the territorial pairs and averaged 725 hectares (Rohner 1997). Density varies in different areas, usually about 1 pair per 5-20 sq km.
Non-Migrant: Y
Locally Migrant: Y
Long Distance Migrant: N
Mobility and Migration Comments: Northern populations partially migratory; some individuals, especially young, found in winter up to a few hundred km south of banding site. Band recoveries indicate that most individuals remain within 80 km of banding site (Johnsgard 1988).
Estuarine Habitat(s): Forested wetland
Palustrine Habitat(s): Riparian
Terrestrial Habitat(s): Cliff, Desert, Forest - Conifer, Forest - Hardwood, Forest - Mixed, Shrubland/chaparral, Woodland - Conifer, Woodland - Hardwood, Woodland - Mixed
Special Habitat Factors: Standing snag/hollow tree
Habitat Comments: Various forested habitats, moist or arid, deciduous or evergreen lowland forest to open temperate woodland, including second-growth forest, swamps, orchards, riverine forest, brushy hillsides, and desert. Very local in tropical lowlands (Hilty and Brown 1986).

Nest sites in different areas include: in trees in old or usurped nests of other birds (e.g., hawk, crow) or squirrel; tree cavities; stumps; rocky ledges; caves; in barns; and on artificial platforms. Usually in heaviest available timber in east; sites more diverse in arid west. Typically does not use same tree nest in successive years.

Adult Food Habits: Carnivore
Immature Food Habits: Carnivore
Food Comments: Opportunistic feeder; eats mainly mammals (commonly mouse to rabbit size) and small to large birds (including hawks and waterfowl). Parents provide up to about 300 g of food per day per nestling.
Adult Phenology: Nocturnal
Immature Phenology: Nocturnal
Length: 56 centimeters
Weight: 1769 grams
Economic Attributes Not yet assessed
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Management Summary
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Monitoring Requirements: Morrell et al. (1991) recommended a standardized survey technique for monitoring long-term status using broadcasts of conspecific vocalizations; surveys should be conducted early in the breeding season, after midnight, and on calm nights with no precipitation.
Population/Occurrence Delineation
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Group Name: Large Owls

Use Class: Breeding
Minimum Criteria for an Occurrence: Evidence of historical breeding, or current and likely recurring breeding, at a given location, minimally a reliable observation of one or more breeding pairs in appropriate habitat. Be cautious about creating EOs for observations that may represent single breeding events outside the normal breeding distribution.
Separation Barriers: None.
Separation Distance for Unsuitable Habitat: 10 km
Separation Distance for Suitable Habitat: 10 km
Separation Justification: Separation distance based conservatively on larger home ranges (greater than 800 hectares). Home ranges generally well over 100 hectares, often over 500 hectares. Northern Hawk-Owl: average 372 hectares (Baekken et al. 1987). Great Horned Owl: average 483 hectares in Yukon (Rohner 1997), average about 106 hectares in Utah (Smith 1969). Barred Owl: average 273-971 hectares (Elody and Sloan 1985, Nicholls and Fuller 1987, Mazur et al. 1998). Great Gray Owl, varied from 239-400 hectares (Craighead and Craighead 1956, Winter 1982). Barn Owl: averages range from 198-921 hectares (Byrd 1982, Colvin 1984, Hegdal and Blaskiewicz 1984, Rosenburg 1986, Byrd and Johnston 1991, Gubanyi 1989).
Inferred Minimum Extent of Habitat Use (when actual extent is unknown): 1.5 km
Inferred Minimum Extent Justification: Based on a conservatively small home range of just under 200 hectares (see Separation Justification).
Date: 02Nov2001
Author: Cannings, S.
Notes: Contains all North American owls larger than Screech-Owls, except Spotted, Long-eared, and Short-eared Owls.

Use Class: Nonbreeding
Minimum Criteria for an Occurrence: Evidence of recurring presence of wintering individuals outside their breeding area (including historical); and potential recurring presence at a given location. Occurrences should be locations where the species is resident for some time during the appropriate season; it is preferable to have observations documenting presence over at least 20 days annually. Be cautious about creating EOs for observations that may represent single events.
Separation Barriers: None.
Separation Distance for Unsuitable Habitat: 10 km
Separation Distance for Suitable Habitat: 10 km
Separation Justification: Separation distance based conservatively on larger home ranges (greater than 800 hectares; see Separation Justification in Breeding class).
Inferred Minimum Extent of Habitat Use (when actual extent is unknown): 1.5 km
Inferred Minimum Extent Justification: Based on a conservatively small home range of just under 200 hectares (see Separation Justification in Breeding Class).
Date: 16Oct2002
Author: Cannings, S.
Notes: Contains all North American owls larger than Screech-Owls, except Spotted, Long-eared, and Short-eared Owls.

Use Class: Roost
Minimum Criteria for an Occurrence: Evidence of recurring, nonbreeding, communal roosting at a given location; reliable observation of multiple individuals roosting in a distinct habitat patch in multiple years. To avoid creating EOs for ephemeral situations, there should be evidence of communal roosting over at least two different (though not necessarily consecutive) nonbreeding seasons.
Separation Barriers: None.
Separation Distance for Unsuitable Habitat: 10 km
Separation Distance for Suitable Habitat: 10 km
Separation Justification: Separation distance is arbitrary. Pertinent biologically based separation criteria do not exist.
Date: 25Oct2012
Author: Hammerson, G
Population/Occurrence Viability
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U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
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Authors/Contributors
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Element Ecology & Life History Edition Date: 05Apr1996
Element Ecology & Life History Author(s): HAMMERSON, G., MINOR REVISIONS BY S. CANNINGS

Zoological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).

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