Great Horned Owl
Great Horned Owls are dark brown with black bars across their body. Their undersides are dark in color and they have white throats. They have tufts of feathers atop their heads that resemble horns, and their eyes are large and yellow.
The Great Horned Owl is one of the largest owls, weighing in at 2-4 pounds with a length of 18-25 inches and a wingspan of 3 to 5 feet. Females are larger than males.
- Owls are efficient predators and have many unique adaptations that increase their hunting abilities.
- The tips of their wing feathers are fringed, allowing them to fly without making any sound.
- Instead of being spherical, owls' eyes are shaped like cylinders to help them see well in the dark.
- The tubular shape of owls' eyes prevents them from rotating in their sockets. To compensate for this, owls have extra vertebrae in their necks that enable them to turn their heads up to 270 degrees around.
- An owl's eye is protected by three eyelids: an upper lid, a lower lid, and a nictating membrane that protects the owl's eye while it is flying.
Great Horned Owls eat a wide variety of prey. Cottontail rabbits make up a large part of their diet, but they will also eat squirrels, skunks, snakes, domestic cats, and a wide variety of birds. At Cosley Zoo, the Great Horned Owls are fed quail, rats, and mice.
Great Horned Owls are one of the earliest nesting birds. Eggs may be laid starting in January or February. Great Horned Owls can use the abandoned nests of other birds, or build nests in rock alcoves, hollows of trees, abandoned buildings, or sometimes on the ground. Females lay an average of 2-3 white eggs, with a maximum of 6. Both the male and female incubate the eggs for 30-35 days. The young are fed by both parents, who fiercely defend their nest site against intruders. The young begin to fly at 45-55 days old.
Shelter and Space Needs
Great Horned Owls are found in woods, mountain forests, desert canyons, marshes, city parks, and urban forests. The owls prefer open areas or nest sites close to the edge of a forest where they can hunt.
It has been difficult to determine the longevity of the Great Horned Owl in the wild. In captivity, these owls have lived into their twenties.
Importance to Man
Great Horned Owls are at the top of the food chain and as predators, they are important for keeping populations of rats and mice under control.
- Because they do not possess a sense of smell, Great Horned Owls are one of the only predators of skunks!
- Since Great Horned Owls nest so early in the year, the parent who is incubating the eggs often becomes covered with snow.
- Groups of small birds will sometimes mob an owl and successfully chase it away.
- If weighed together, a Great Horned Owl's eyes will weigh almost one ounce - more than those of a 200 pound human!