|THE ROBINSON LIBRARY|
|The Robinson Library >> Science >> Zoology >> Birds >> Order Strigiformes|
|Great Horned Owl
Bubo virginianus [byoo' bO vir jin' E an nus]
The largest owl in North America is 1½-2 feet long, has a wingspread of up to 5 feet, and weighs 3-3½ pounds. Its large feet, which are feathered to the ends of the toes, are armed with very sharp talons capable of killing most prey instantly. Coloration ranges from reddish brown to grey, sometimes even black and white, with dark bars on the underside and a white band of feathers on the upper breast. The large yellow-orange eyes are usually bordered by an orange-buff facial disk. The species is distinguished by the tufts of feathers that somewhat resemble horns; although they are often referred to as ear tufts they have nothing to do with hearing. There is no difference in coloration between males and females, but females are up to 20 percent larger than males. Juveniles resemble adults.
Distribution and Habitat
Great horned owls inhabit a wide variety of habitats, from dense forests to deserts and plains, and can even be seen in urban areas. They are found throughout North America except for the northernmost reaches of Alaska and Canada, through Central America and into parts of South America.
Great horned owls prey on large rodents, rabbits, reptiles, amphibians, large arthropods, and fish. They are also the only owls to regularly eat skunks. They hunt by either perching and waiting for prey to come near or by gliding slowly above the ground and pouncing; they will also walk on the ground to capture small prey, and will even wade into shallow water to snatch up frogs and fish. A strong grip and powerful body allows a great horned owl to take prey two to three times heavier than itself.
Courtship usually begins in mid-winter, when both males and females hoot and display to attract each other. Great horned owls do not build their own nests, relying instead on the nests of other large birds, squirrel nests, or a hollow tree. Two to three white eggs are laid, one egg at a time. They are incubated by the female alone for 26-35 days, with the male providing food for the female and protecting the nest. Chicks are able to fly at about 35 days of age, and able to fend for themselves at about five months.
Mating pairs may come together several years in a row, but do not remain together outside of the breeding season.
Other Habits and Behaviors
The great horned owl is most active from dusk to dawn, but may be seen in the late afternoon or early morning in some areas. Both sexes are territorial and will defend an area of up to one square mile, though usually only with warning calls.
The male's characteristic "hoo-hoo hooooo hoo-hoo" call can be heard several miles away on a still night. Both sexes hoot, but the males' hoot is lower-pitched than the females'. Other sounds produced by great horned owls include a "krrooo-oo" or screaming note when attacking intruders, "whaa whaaa-a-a-aark" when disturbed, as well as cat-like sounds, barks, shrieks, coos, and beak snapping.
Great horned owls are often mobbed and harassed by large mobs of crows, who will often make it a point to congregate where owls are perching. This behavior probably stems from the fact that the great horned is one of the most prevalent predators of crows.
The great horned owl was first observed in the early Virginia colonies, which explains it's scientific name. The first published description of the species was written by Johann Gmelin in 1788.
|The Robinson Library
>> Zoology >> Birds >> Order Strigiformes
This page was last updated on June 15, 2017.