The Great Horned Owl (Bubo virginianus), also known as the “Flying Tiger,” found virtually throughout the Americas, will attack any medium-sized animal or bird, porcupine or skunk, duck or grouse. The bird is courageous, powerful and bloodthirsty, gliding through the woods and over meadows as a shadow of certain and sudden death.
In spite of heavy persecution from shooting, trapping, poisoning, road casualties, and more, great horned owls are common. How could that be possible? Partly because they are secretive. Even in built-up areas, they are difficult to locate. And they are versatile. They hunt less by listening for the prey than many owls do. Highly skillful and deadly in its pursuit of game, they hunt by perching at vantage points and then making short flights to capture the prey.
An adult owl is solitary from July to December when pairs begin to form and roost together. Usually, great horned owls attract a mate and become reproductive during the second to the third year of life. In North America, the Great Horned Owl begins to breed in the cold of winter. Two or three eggs are laid, usually in the old nest of a large hawk or crow, sometimes in a hollow tree or a cave.
These owls can nest in a wide variety of sites, including stick nests of raptors, tree cavities, deserted buildings, and nest platforms. The female lays a clutch of two to three eggs. The young remain in the nest until about late spring and are dependent on the parents for food until late summer. Each chick eats about one pound per day. When food is scarce, only one owlet may survive, with siblings occasionally killing each other in the battle for food, an often observed behavior in raptors and other large birds. Surviving young leave the nest after they have nearly achieved the adult weight of about three and a half pounds.
Calls are many and various, but the common one is a series of muffled hoots: hoo, hoo-hoo, hoooo-hoo. The male’s voice is higher-pitched than the female’s, and a pair in concert seem to harmonize, often in thirds.
The great horned owls are so strong that they occasionally take mammals ranging in size up to the grey fox. Skunks, other owls, and stray house cats are not uncommon prey. Snakes and amphibians provide a significant portion of their diets. However, their preferred prey consists of hares, rabbits, and small rodents.
Among the owls that live in Canada and the United States, the great horned owl has the largest eyes. Its eyes are equal in size to those of an adult human, who would weigh at least 50 times more than the owl. The eye of a great horned owl is so large, the entire skull of a house sparrow can fit inside it.
- Max R. Terman – Messages From An Owl
- Paul Bannick, Martyn Stewart – The Owl And The Woodpecker: Encounters With North America’s Most Iconic Birds
- Wayne Lynch – Canada: A Complete Guide To Their Biology And Behavior