Great Horned Owl

SCIENTIFIC NAME

Bubo virginianus

CLASSIFICATION

Class:	Aves
Order:	Strigiformes
Family:	Strigidae
Genus:	Bubo
Species:	virginianus

SIZE

Length:	Male:	17-22 inches
	Female:	18-25 inches
Weight:	Male:	2-3 pounds
	Female:	2 1/2-3 1/2 pounds
Wingspan:	Male:	35-50 inches
	Female:	45-60 inches

APPEARANCE:

There are about ten different subspecies of Great Horned Owls in its present range, and they vary in size and color; however, the general appearance of each race is similar. In the New World, only the Great Gray Owl and the Snowy Owl are larger.

The Great Horned Owl is characterized by large ear tufts, yellow eyes, an owl’s facial disk, a lack of a visible neck, and feathers down to the talons. As with most birds of prey, the females are larger in size.

Plumage varies from very dark in the Pacific Northwest to very pale in the Arctic. A typical adult is mottled gray-brown above, buff below, barred dark brown, with a tawny face and a distinctive white throat patch. Juvenile or immature owls are similar to adults but have a lighter or more rufous color until they mature. Their ear tufts are smaller and the white throat patch is less distinctive.

RANGE/DISTRIBUTION:

The Great Horned Owl is a bird of the New World and has a present range that covers both North and South America from the Arctic to the Straits of Magellan.

HABITAT/TERRITORY SIZE:

Habitats vary from woodlands to open country, urban parks to semi-deserts. They also live from low altitudes to below the timberline high in the mountains.

MIGRATION:

The Great Horned Owl is a non-migratory bird.

DIET:

Great Horned Owls capture a wide variety of prey that ranges in size from shrews and mice, to jack rabbits. They have been known to take prey as large as a porcupine. They also eat fish, scorpions, and a variety of birds, including the young of other raptors. These owls have been found dining on skunks. It appears that the skunk’s odor has little effect in deterring the Great Horned Owl.

HUNTING METHOD:

The Great Horned Owl is crepuscular, which means that it will hunt most of the time at sunrise and sunset. Great Horned Owls typically hunt from a perch. Keen hearing would be useless if the owl itself made a lot of noise, so owls have evolved the ability to fly in nearly complete silence due to the soft fringes on the leading wing feathers. When hunting, owls will glide silently down on unsuspecting prey. With the silent flight, the Great Horned Owl is usually successful in capturing its prey.

BREEDING INFORMATION:

Great Horned Owls are solitary birds except during the breeding season when they are found in family groups. Owls begin to pair up as early as February and raise only one brood each season.

They are not very good nest builders so nests are often crude structures of sticks and twigs constructed in hollow trees or deserted buildings. They will often use abandoned hawk or crow nests instead of building their own.

The round-shaped eggs are laid at intervals, as often as every other day, with 2 to 6 being the average number. Owls begin to incubate the eggs from the time the first one is laid, so the young hatch out at intervals and a nest may contain young of different ages and sizes. Both the male and the female care for the nest, incubate the eggs, feed the young, and defend the home territory against intruders. The young remain in the nest until they are 9 to 10 weeks old and are able to fly. Afterwards, they follow the parents about and are fed by them until they can fend for themselves.

BEHAVIOR:

The Great Horned Owl is said to be one of the fiercest of the birds of prey. Eastern ones are known to be more aggressive than the western representatives. This raptor has been known to drive a Bald Eagle away from its nest.
Their vocalizations include the very distinctive low, hooting, who-who-whowhowho-whoo-whooo. The female voice is usually lower and deeper in tone than the males.

They will become much more vocal while courting.

The tufts of feathers on top of the owl’s head, which are called “horns” are not part of the ear apparatus, but they can be raised or lowered as an indicator of owl’s mood and can be used in communicating with another owl.

STATUS:

Great Horned Owls are the most common large owls found in North America.

FOLKLORE AND MYTHS:

Stories about owls can be found throughout history in many cultures, mythology, and even the Bible. Some liked the owl, but to many they were feared and associated with evil and death. They were often considered a messenger of death, if you saw an owl or heard its sound, death to someone you knew was eminent.

In Sicily, the “horned” owl is especially feared. It is believed it sings near the house of a sick man three days before his death.

Bad weather is foretold by the hooting of a horned owl.

In some Native American tribes, the Great Horned Owl is a guardian spirit of the medicine man.

BIBLIOGRAPHY:

• “Owls: An Introduction for the Amateur Naturalist”, by Gordon Dee Alcorn, 1986, pages 62-72.
• “Life Histories of North American Birds of Prey”, by Arthur Cleveland Bent, 1961, pages 295-322.
• “A Natural History of American Birds”, by Edward Forbush, 1955, pages 265-267.
• “Great Horned Owls.” Packet from Saturday Academy class, Birds of Prey. Received on 10-13-90.
• “Birds of Prey of the World”, by Mary Louise Grossman and John Hamlet, 1964, page 422.
• “Idaho’s Birds of Prey: part 2: Owls.” Packet from Saturday Academy class, Birds of Prey. Received on 10-13-90.
• “North American Owls: Biology and Natural History”, by Paul A. Johnsgard, 1988, pages 129-135.
• “Oregon’s Owls.” Packet from Saturday Academy class, Birds of Prey. Received on 10-13-90.
• Cathi Wright; Oregon Zoo, Assistant Show Coordinator.