GREAT HORNED OWL

 


Scientific name:  (Bubo virginianus)




Great Horned Owl 


Classification and Range


Great horned owls are in the genus Bubo, and the family Strigidae or “typical owls.” There are 12 species of Bubo or “eagle owls” worldwide, however, the great horned owl is the only Bubo species found in the Americas. Great horned owls breed throughout North, Central and South America from western and central Alaska through central and eastern Canada south to Tierra del Fuego at the tip of South America.

Habitat

Great horned owls occupy a greater variety of habitats than any other owl in North America. They are birds of coniferous, deciduous and mixed forests, desert, swamp, woodland, prairies, farmland and large urban parks. They prefer areas with open areas for hunting and at least a few scattered trees for perching. 

Physical Characteristics


Great horned owls are large dark gray-brown owls with distinct feathered “ear tufts” and large yellow eyes. They have a buff facial disc outlined in black and a distinct white patch on the throat. The breast is tawny with many tiny dark bars; the back is darker and mottled. They average 22 inches (55 cm) in length with a wingspan of about 45 inches (113 cm). Weight typically ranges from 2.5 to 4.5 pounds (1.1-2.0 kg). As with most owls the females are larger than the males but otherwise they are similar in appearance.


Life Span

Great horned owls have lived more than 35 years in captivity.


Diet

In the wild: Great horned owls eat an extremely wide variety of prey. Over 250 prey species have been identified, far more than any other bird in North America. Small mammals such as jackrabbits, cottontails, skunks, meadow voles and mice make up the majority of the great horned owls diet but they will also eat insects, reptiles and birds up to the size of geese and herons.


Reproduction


Great horned owls are one of the earliest nesting birds. Pairs may begin roosting together in early December and females may begin incubating eggs as early as late February. One to six eggs are laid in an old crow or red-tailed hawk nest, tree or cactus crotch, or cavity. Females perform all incubating and brooding duties while their mate supplies them with food. 

Life Cycle


Young owls grow quickly and by 6 to 7 weeks the nest becomes crowded. The young birds soon leave the nest and move onto surrounding branches where they hide and wait for food. These “branching” young begin testing their wings at 6 to 7 weeks. At 9 to 10 weeks the young owls begin to fly and within a few more weeks the young birds will start to fend for themselves. They will remain dependent on the adults for some time while they acquire and hone their hunting skills and will finally disperse from the home range of the adults in the fall.

Calls of the Wild

Great horned owls are fairly sedentary birds and are a common year-round residence throughout much of their range. They maintain their territory for much of the year. The territorial song of the male is a series of four to five deep hoots, Hoo, hoo-oo, hoo, hoo.” The female responds with six to eight hoots, “Hoo, hoo-hoo-hoo, hooo-oo, hoo-oo.” Mated pairs hoot back and forth in a duet. Although soft, their call is booming and far-reaching, and will often send small birds and mammals in search of cover. Great horned owls will drive all other owls from their territory and their presence will also influence the distribution of diurnal raptors, such as red-tailed hawks.


Conservation Connection

Due to their adaptability to a variety of habitat types and prey species, great horned owls have remained common, despite continuing persecution over much of their range. Habitat destruction, road fatalities and indiscriminate shooting remain a concern for great horned. owl populations in many areas.


Ref:  Woodland Park Zoo, Seattle, WA