|Great Horned Owl|
|Great Horned Owl (Ontario, Canada)|
| Bubo virginianus|
Strix virginiana Gmelin, 1788
The Great Horned Owl, (Bubo virginianus; BEW-boh ver-jin-ih-AY-nus), also known as the Tiger Owl, is a large owl native to the Americas. It is an adaptable bird with a vast range and is the most widely distributed true owl in the Americas. It is closely related to the Lesser Horned Owl, which may be a separate species.
They measure 45–64 cm (18–25 in) in length, they weigh 900–2,503 g (1.984–5.518 lb) and their wingspan is 91–152 cm (36–60 in). Females are 10-20% larger than males, they can weigh on average, 700 g (25 oz) more than the male.
The Great Horned Owl is a large owl with iconic yellow-orange eyes and two prominent feather tufts on the tops of their heads. These tufts gave the owl it's best-known name. The plumage of the owl can vary from a reddish brown to a grey or black and white; in Canada, can range from very dark in the Maritimes to almost as pale as the Snowy Owl. The underside is a light grey with dark bars and a white band of feathers on the throat. They have large feet that are feathered to the ends of the toes. The immature birds tend to resemble the adults.
In flight, as large as our American hawks; looks neckless and large-headed.
Snowy Owl is similar in size, but only the subarctic race of the Great Horned could be confused with the female Snowy.
The Lesser Horned Owl is smaller, and its range hardly overlaps in range; it is paler, with a smaller bill and weaker talons; below, it is more finely barred dark and light. It also has a different vocalization.
In northern parts of its American range, its distinctive calls may be confused with the Great Grey Owl. However, it lacks ear tufts and a has a large, rounded head, small yellow eyes and grey plumage with dark markings.
Nocturnal. In Colombia, it roosts and nests in tall palms at Carimagua, ne Meta (S. Furniss).
On December 4, 2014, a man named Steve Spitzer took video and photos of an owl swimming in Lake Michigan, Chicago. It was attempted to escape Peregrines that were harassing it.
It takes any prey from insect size to hares, geese and turkeys. In Colombia, it preys upon a variety of medium-sized mammals, such as coatis and rabbits, and two species of snipe in the Andes (Lehmann, 1946).
Here are some examples of its prey:
- *=Species not identified
Table based on: 
Call is a series of three to eight loud, deep hoots; second and third hoots often short and rapid, repeated fully or in part at intervals of several seconds, has great carrying power. Juvenile birds give off a raspy begging call.
The young follow the adults when on the wing, utter blood-curdling screams (hunger cries). Adults lean forward when hooting, vibrate their white throat feathers and lift their short tails, and respond to imitation of their cries.
It usually uses the nests of Red-tailed Hawk, Bald Eagle, heron and crow, or occasionally an old leaf nest of a squirrel; 15–70 ft (4.6–21.3 m) up. Also, in rocky caves of cliffs, in hollows of trees and even on the ground.
- ^ BirdLife International (BLI) (2008). Bubo virginianus. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 15 April 2012.
- ^ a b c d e f g Terres, John K. (1980). The Audubon Society Encyclopedia of North American Birds. Alfred A. Knopf, Inc. ISBN 0394466519.
- ^ Holt, D.W., Berkley, R., Deppe, C., Enríquez Rocha, P., Petersen, J.L., Rangel Salazar, J.L., Segars, K.P. & Wood, K.L. (1999). Magellanic Horned Owl (Bubo magellanicus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/55007 on 11 October 2015).
- ^ Matthew Graul and Barbara Holzman, PhD. (editor) (12/16/2003). "Great Horned Owl". San Francisco State University. Retrieved 12-12-2019. Check date values in:
- ^ a b c d e Mikkola, Heimo (2012). Owls of the World: A Photographic Guide. Firefly Books Ltd. ISBN 9781770851368.
- ^ a b c d e f Stokes, Donald W. and Stokes, Lilian Q. (2010). Stokes Field Guide to the Birds of North America. Little, Brown and Company. ISBN 9770316010504 Check
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- ^ a b Peterson, Roger Tory (1980). A Field Guide to the Birds East of the Rockies. Houghton Mifflin Company. ISBN 039526619X.
- ^ Peterson, Roger Tory (1961). A Field Guide to Western Birds. Houghton Mifflin Company. ISBN 039513692X.
- ^ Bellrose, Frank C. and The Audubon Society (1983). The Audubon Society Master Guide to Birding. National Geographic Society. ISBN 1426200722.
- ^ a b c Dunn, Jon L. and Alderfer, Jonathan (2011). National Geographic Guide to the Birds of North America. National Geographic Society. ISBN 1426200722.
- ^ a b Hilty, Steven L.; Brown, William L.; Tudor, Guy (1986). A Guide to the Birds of Colombia. Princeton University Press. ISBN 069108372X.
- ^ Arciero, Ryan (4 December 2014). "Owl swimming Lake Michigan: Video of owl swimming with skill, butterfly stroke". The Examiner. http://www.examiner.com/article/owl-swimming-lake-michigan-video-of-owl-swimming-with-skill-butterfly-stroke. Retrieved 12 January 2015.
- ^ Harrison, Colin and Greensmith, Alan (1993). Birds of the World. Dorling Kindersley Inc. ISBN 1564582965.
- ^ Lehmann, V.F.C. (1946). Two new birds from the Andes of Colombia. Auk 63:218-223.
- ^ a b Kittredge, V.C., Wilson, P.W., and Caire, W. 2006. An updated checklist of the food items of the great horned owl (Bubo virginianus: Strigiformes: Strigidae) in Oklahoma. Proceedings of the Oklahoma Academy of Science, 86:33-38.
- ^ a b c d e f g h i j k l m n o p q r Baumgartner AM, Baumgartner FM. 1944. Hawks and owls in Oklahoma 1939-1942: food habits and population changes. Wilson Bull 56(4):209-215.
- ^ a b c d e f g h i j k l m n o Schemnitz SD, Ables E. 1962. [Notes on the food habits of the Great Horned Owl in western Oklahoma Notes on the food habits of the Great Horned Owl in western Oklahoma]. Condor 64:328-329.
- ^ a b c d e f g h Sutton GM. 1967. Oklahoma Birds. Norman (OK): University of Oklahoma Press. 257 p
- ^ a b c Baumgartner AM, Baumgartner FM. 1992. [[Oklahoma Bird Life]]. Norman (OK): University Oklahoma Press. 532 p.
- ^ a b Chesser RK, Kennedy ML. 1976. Predation on the free-tailed bat by the Great Horned Owl. Bull Okla Ornith Soc 9:1-3.
- ^ John H. Boyd III (July 6, 2011). "PALEOGNATHS and ANSERIFORMES Ratites, Tinamous, and Waterfowl". TiF Checklist. Retrieved 12-12-2019. Check date values in:
- ^ Byre VJ. 1995. Proximal nesting of Barred Owls, Great Horned Owls and Red-shouldered Hawks in Cleveland County, Oklahoma. Bull Okla Ornith Soc 28:22-24.
- ^ John H. Boyd III (September 12, 2011). "CORE PASSEROIDEA IV: Emberizidae and Passerellidae". TiF Checklist. Retrieved 12-12-2019. Check date values in:
- ^ a b c d e f g h Tyler JD, Jensen JF. 1981. Notes on foods of Great Horned Owls (Bubo virginianus) in Jackson County, Oklahoma. Proc Okla Acad Sci 61:28-30.
- ^ a b c Smith KS. 1996. A new microtine (Microtus) record for Kiowa County, Oklahoma. Proc Okla Acad Sci 76:97-98.
- ^ a b c d Smith KS. 1993. Owl pellets reveal Cryptotis parva, a new record for Caddo County, Oklahoma. Proc Okla Acad Sci 73:29-30.
- ^ Twente JW. 1954. Predation on bats by hawks and owls. Wilson Bull 66:135-136.
- ^ Taylor J. 1964. Noteworthy predation on the guano bat. J Mamm 45:300-301.
- ^ Perry AE, Rogers G. 1964. Predation by the Great Horned Owl (Bubo virginianus) on young Mexican freetailed bats (Tadarida brasiliensis Mexicana) in Major County, Oklahoma. Southw Nat 9:205.
- ^ Looney MW. 1972. Predation on bats by hawks and owls. Bull Okla Ornith Soc 5:1-4.
- ^ Caire W, Ports M. 1981. An adaptive method of predation by Bubo virginianus (Strigiformes: Strigidae) on Mexican free-tailed bats (Chiroptera: Mollosidae). Southw Nat 26:69-70.
- ^ Truslow, F.K (1966). Ground-nesting great horned owl: A photographic study. Living Bird, 5th annual, pp. 177-86.
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