Great Horned Owl

Great Sand Dunes National Park and Preserve, Public domain, via Wikimedia Commons

Excerpt from Marvels of Creation: Breathtaking Birds

by Buddy Davis and Kay Davis on April 5, 2013

The great horned owl is the largest and most powerful of all North American owls.

Great Horned Owl

The great horned owl lives in most areas of North and South America including forests, deserts, and even in cities. Sometimes it is possible to locate owls by listening for their very distinctive hooting call.

The feathers of the horned owl are dark brown with black markings on the upper part of the body and lighter brown with black horizontal bars on the lower part. Owls have large forward-pointing eyes, which are circled by large zones known as facial disks, two areas usually white in color and half-moon shaped. This particular species has its ears covered by tufts of feathers that look like horns and give the great horned owl its name. The bowl shape of the facial disks helps funnel sound to the ears, giving the owl excellent hearing.

Like most birds, it has four toes, but while most birds have three front toes and one in back, the owl can rotate its outer third toe to the back, giving it two in front and two in back. This helps the mighty raptor capture and grip its prey more easily. The curved, pointed beak of the owl can rip its prey to shreds, but it likes to swallow its prey whole if possible.

Sight is especially acute in this bird of prey. Their large eyes with a bright yellow iris are designed with a highly developed lens and cornea and a special opaque membrane on their eyelid. This third eyelid is called the nictitating membrane and it is used to protect the sensitive retina from the bright light of the daytime. Like other birds, the eyes are fixed in their sockets so that the owl cannot move them up and down or to the sides. Therefore, it must turn its whole head to move the eyes. They have a frontal vision field of 70 percent. However, they can rotate their heads very rapidly about 270 degrees, which increases their vision field tremendously.

As a nocturnal hunter, the owl needs outstanding vision, but also relies on its acute hearing to locate and catch food. The ear structure is very well designed with the right and left ears often differently shaped. A moveable skin fold along the front edge of the ears reflects sound waves from behind them.

The diet of the great horned owl is mice, rabbits, frogs, squirrels, muskrats, snakes, opossums, and even skunks. The owl can stealthily attack its prey because of serrations on the front edge of the first primary feathers allowing it to fly silently. They can attack at speeds of up to 40 mph (64 km/hr).

The great horned owl does not usually build a nest but uses tree hollows, burrows, or the nests of other birds such as eagles or hawks. The female lays 1 to 5 eggs and incubates them for 35 days. The young can fly at 9 to 10 weeks.

Great Horned Owl

Strigiformes • Strigidae • Bubo virginianus

Weight: 8 pounds (4 kg)
Length: 17–21 inches (43–53 cm)
Wing Span: 35–60 inches (92–154 cm)
Life Span: 29 years
Special Design Feature: The great horned owl’s eyes are located toward the front of its head but the head can be rotated 270 degrees, greatly increasing its vision range.
Did you know? The great horned owl is the largest and most powerful of all North American owls.