Great Horned Owl (Bubo virginianus)
The Great Horned Owls is a very large, powerful owl with prominent ear-tufts. It was first seen in the Virginia colonies, so its species name “virginianus” was created from the Latinised form of this name. Great Horned Owls are sometimes known as Hoot Owls, Cat Owls or Winged Tigers. This powerful predator can take down birds and mammals even larger than itself, but it also dines on daintier fare such as tiny scorpions, mice, and frogs. It’s one of the most common owls in North America.
The facial disc is rusty-brown to ochre-buff, paler around the eyes, with a prominent blackish rim on each side. Eyes are yellow, with blackish edged eyelids. The bill is greyish. Eyebrows are prominent and whitish. Ear-tufts are long and tousled. The Ear-Tufts are not actually their ears but are just a feathers. It may have developed as a mood indicator to other Great Horned Owls. Depending on their mood the tufts can be upright or laid back along the head. From a photographic stand it is always exciting to have your Great Horned Owl pictures with the tufts in the upright position.
There is considerable variation in the colouration depending on where they are found but the body shape is consistent. The Great Horned Owl is heavily built with a barrel shape, large round head and large broad wings. The chest and belly area is usually light in colour with dark barring, however the bars can be reddish or darker brown. The back is generally a darker mottled brown.
They have a body length of 18-24 inches, wingspan of 39-57 inches and a body weight of 36-88 ounces.
Found all across North America up to the northern tree line, Great Horned Owls usually gravitate toward secondary-growth woodlands, swamps, orchards, and agricultural areas, but they are found in a wide variety of deciduous, coniferous or mixed forests. In some areas, such as the southern Appalachians, they prefer old-growth stands. Their home range usually includes some open habitat—such as fields, wetlands, pastures, or croplands—as well as forest. In deserts, they may use cliffs or juniper for nesting. Great Horned Owls are also fairly common in wooded parks, suburban area, and even cities.
Great Horned Owls have the most diverse diet of all North American raptors. Their prey range in size from tiny rodents and scorpions to hares, skunks, geese, and raptors. They eat mostly mammals and birds—especially rabbits, hares, mice, and American Coots, but also many other species including voles, moles, shrews, rats, gophers, chipmunks, squirrels, woodchucks, marmots, prairie dogs, bats, skunks, house cats, porcupines, ducks, loons, mergansers, grebes, rails, owls, hawks, crows, ravens, doves, and starlings. They supplement their diet with reptiles, insects, fish, invertebrates, and sometimes carrion. Although they are usually nocturnal hunters, Great Horned Owls sometimes hunt in broad daylight. After spotting their prey from a perch, they pursue it on the wing over woodland edges, meadows, wetlands, open water, or other habitats. They may walk along the ground to stalk small prey around bushes or other obstacles.
Nesting begins in January to February. If they find each other interesting they go through a courting ritual which include bowing to each other and beak rubbing. Like other owls they do not make their own nests but will reuse nest from larger birds like herons, hawks, crows and ravens. They will also use large tree cavities or the hollowed out tree tops, abandoned buildings and artificial platforms. They are extremely aggressive when defending the nest and will continue to attack until the intruder is killed or driven off. Normally, two to four eggs are laid and incubated by the female only for 26-35 days. Young start roaming from the nest onto nearby branches at 6 to 7 weeks, when they are called “branchers”, but cannot fly well until 9 to 10 weeks old. They are fed for another few weeks as they are slowly weaned.
The young will remain in their parent territory over the summer until the fall when they move out and find their own territories and mates. A pair will maintain their breeding grounds for a number of years if there is sufficient food supply. However, while they remain a pair they often separate in their territory and only come together during their breeding period.
There are a number of similar owls in other parts of the world that fill in the environmental niche as the Great Horned Owl but these are found only in the new world of North and South America.
Subspecies: B. v. virginianus, B. v. elachistus, B. v. heterocnemis, B. v. lagophonus, B. v. mayensis, B. v. mesembrinus, B. v. nacurutu, B. v. nigrescens, B. v. pacificus, B. v. pallescens, B. v. saturatus, B. v. subarcticus, B. v. wapacuthu, B. v. deserti
References: Cornell Labs of Ornithology, The Owl Pages, Wikipedia