Great Horned Owl

Bubo virginianus (Bubo in Latin means “great horned, or, eagle owl.”)

Owls

Prepared by

Ann Walton

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Subspecies differ greatly in size and coloring; the following description, therefore, refers to our local subspecies, virginianus:

Length: 18-25 inches
Wingspan: 35-60 inches
Weight: male average:1318g., female average: 1769 g.

Adult males and females have similar coloring. Upper parts dusky to dark sooty brown, broken by coarse horizontal mottling of various shades of browns; underparts vary from pale brown to tawny with dark brown horizontal barring. The duskier crown and nape are broadly striped, this pattern continuing onto forehead. The face has dull white eyebrows with tawny facial disks outlined in black. Bill, slate black; eyes, bright lemon-yellow. Most importantly, prominent widely spaced, slanted ear tufts and a white throat and bib distinguish this owl from any other large North American owl. The Great Horned Owl also appears thick and bulky, unlike the narrow profile of the Long-eared Owl.

Immature initially covered with white down, later becoming ochraceous or buff with indefinite black barring.

The common call is a soft, low-pitched, dove-like 4-7 note hooting.

Distribution

Western and central Alaska, south throughout southern Canada, the US, Central and South America to Tierra del Fuego.

Habitat

Ubiquitous: Lowland to mountainous regions, but not above treeline. Can be found from forested to open areas, including deserts. Also has commonly adapted to residential areas and cities.

Feeding

Mice, voles, and rabbits comprise most of its diet. However, it ingests a diversity of foods, including large insects, snakes, frogs, fish, squirrels, skunks(a favorite, unfortunately for the rehabber), woodchucks, opossums, domestic cats, medium-sized birds(jays, woodpeckers), crows, pheasants, geese, turkeys, chickens, and even swans, herons, hawks, and small owls. Although mostly nocturnal, it will also hunt in the early dawn and just before dark; often, during the daylight hours, it will perch in the open, on barns and on exposed tree branches, for example. Hunting is accomplished mainly by perching until prey has been detected, then making short capturing flights.

Breeding

February-March. Interestingly, nest sites are variable among subspecies, from trees(cavities and branch nests), logs, caves, cliffs, and quarries to swamps and parks. In the midwest, it prefers deep woods, rather than edges; it often uses the large stick nests of resident hawks, choosing those that are 30-50 feet high. Live trees of all types seem to be favored over dead ones. Will occasionally add roots, bark, and moss to the nest, and lightly line it with feathers and down. The clutch is 1-6 eggs.

Movements

Mostly sedentary; northern populations will follow food supply.

Status

In spite of its declining environment, population seems stable because of its great ability to adapt to changing conditions.