Owls: A Comprehensive Guide to These Majestic Birds of Prey

Owls

Introduction to Owls

Owl, a bird of prey found in most parts of the world except Antarctica. Owls have large eyes and round faces. Many kinds of owls have two tufts of feathers (called ear tufts, though they are not part of the ears) on the top of the head. The number of owls is becoming smaller because the woodlands in which they live are being destroyed.

Owls vary widely in size according to the species. The females are slightly larger than the males. Like most birds of prey, owls have hooked beaks and curved talons (claws). The birds are mostly brown or mostly gray and many kinds are barred or speckled. Owls have stout bodies, rounded wings, and short, square tails.

Owls have hooked beaks and curved talons.

Many owls are active only at night. Because of their keen senses of sight and hearing, they can hunt successfully in dim light or in the dark. Night-hunting owls can also see in daylight. An owl must turn its head in order to see in any direction other than straight ahead. It can turn its head completely around so that it can see directly behind it.

In some species the two ear openings, located on the side of the head behind the facial feathers, are of different shape. This difference helps the owl find the direction from which a sound is coming. Owls' feathers are soft and edged with small, hairlike filaments that deaden the sound of their flight. Their silent flight helps owls to surprise prey.

Owls are associated in legend with wisdom and with evil spirits. Their reputation for wisdom was probably suggested by their round faces and eyes. Superstition considers owls to be evil spirits forewarning of evil events. This reputation probably comes from their haunting calls, silent flight, and tendency to nest in deserted buildings.

Owls kill many rodents that are nuisances to man. When food is scarce, owls occasionally raid poultry yards and eat game birds, but in general, they do more good than harm.

How is an Owl a Bird of Prey?

Like other birds of prey, owls have bodies that are especially well adapted for hunting and killing animals. Owls have powerful legs and feet. They also have sharp claws, or talons, that can pierce and grab small animals. Most owls have feathers on their legs and toes. The feathers protect them from cold—and from prey that might bite back.

Birds of prey have sharp, curved bills that are very strong. The upper and lower parts of the bill can work like powerful scissors to tear and cut meat. Owls swallow small prey whole.

Where in the World Do Owls Live?

There are more than 140 different kinds of owls. Owls live almost everywhere in the world where there is land, except Antarctica and some islands.

Grasslands are home to some kinds of owls. These owls include barn owls, great horned owls, and burrowing owls. Great horned owls, burrowing owls, and elf owls can also survive in the desert, where there is little or no rainfall.

Spotted owls live in forests of spruce or fir. Many owls live in different kinds of woodlands. The barred owl and the great gray owl live in hardwood forests. Northern hawk owls like the open woods.

One owl, the snowy owl, even lives on the frozen tundra. The tundra is a large, almost flat plain of the Arctic region. There are no trees in the tundra.

How Do Feathers Help Owls Hear?

Those tufts of feathers that stick up like ears on an owl’s head aren’t ears at all. No one knows what they are for. An owl’s large ear openings are at the sides of its head. The stiff feathers around the eyes act a lot like dish antennas. They reflect sound toward the ear openings.

Suppose an owl hears an animal sound. The sound is louder in one ear than in the other. This tells the owl that the animal is closer on that side. The owl turns its head until the sound is equally loud in both ears. Then it knows it is facing the animal.

An owl can also “hear” the height of a sound. It turns and tilts its head until it gets a perfect “fix” on where the sound is coming from. Owls eat mostly small animals that creep through grass and leaves on the ground. An owl’s keen ears can hear the tiny sounds of prey—even when those sounds come from under snow.

Who-o-o Is It?

It’s not easy to spot an owl. But you may be able to hear one.

Different kinds of owls have many different calls. Some, like this great horned owl, seem to say “who-o-o, who-o-o” when they hoot. Others whistle, hiss, click, or chatter. One even makes a rasp that sounds like a rattlesnake. An owl hoots to claim its territory and to attract a mate. The word owl may in fact come from the hooting sound that the bird makes.

In the sign language of some Native American groups, the word for owl was formed with the hands. The sign is made by spreading fingers at each shoulder and flapping them. (This is the general sign for bird.) Then, to specify owl, the signer uses thumbs and index fingers to form two circles, which are put over the eyes.

Habits of Owls

Feeding

Mice and rats are the main food of owls. The larger owls also eat larger animals, such as rabbits, skunks, and ducks. When rodents are scarce, owls catch smaller animals, including insects.

A hunting owl locates its prey primarily by sight during the day and by sound at night. It flies silently over the prey, brings its talons forward, and lands on the animal. After killing the prey, the owl lifts the catch to its mouth with a foot and then flies off to its eating spot, usually a tree. The stomach of an owl does not digest fur, feathers, and bones. These remains are rolled into oblong pellets which the owl coughs up a few hours after eating. The ground at the base of an owl's eating tree and the area around a nest are often littered with these pellets.

What Helps Owls Hunt at Night?

Owls are night-time hunters. Most owls have huge, staring eyes. They also have keen hearing. Their eyes and ears help them hunt at night.

In dim light, owls can see better than most other animals. The eyes of most owls have very large pupils. The pupil, or black part of the eye, is really an opening. An owl’s pupil can open almost to the width of the whole eye. Thus, the pupil can take in every bit of light there is.

Most birds have eyes at each side of their head. They see a different scene with each eye. But an owl’s eyes are at the front of its head. The owl sees the same scene with both eyes, just as a human does. An owl cannot move its eyes in their sockets, however. In order to see what is beside or behind it, the owl turns its whole head.

What Makes an Owl a Silent Hunter?

The night is dark. An owl hears exactly where a mouse is. It sees the mouse move in the grass. Suddenly the owl swoops silently down. It grabs the mouse with its talons.

How can the owl be so quiet? The soft, loose edges of the owl’s flight feathers muffle the sound of its wings. Thus, the owl can silently sneak up on its prey. The flapping sounds made by most other birds of prey would have scared the mouse away.

What Do Owls Eat?

The favorite foods of North American owls are insects and rodents. Rodents are small animals such as mice, rats, shrews, and voles. Most owls stay in one place all year long, so they have to eat what they can find in each season. Owls also eat worms, frogs, lizards, smaller birds, and even larger animals such as rabbits and weasels. Some kinds of owls catch and eat fish. Owls can kill animals as large as they are or even larger.

When an owl lands on its prey, the owl hits the prey with its feet. If the prey is still alive, it breaks the animal’s neck with a quick bite. Then it carries its prey up to a branch to eat.

What Are Owl Pellets?

When owls eat small prey, they usually swallow the animal whole. They tear larger prey into smaller pieces. However they eat, owls swallow many parts—bones, claws, fur, and feathers—that they cannot digest.

Juices in an owl’s intestine dissolve and digest the usable parts of prey—the meat. Bones, claws, and other indigestible parts are squeezed into a hard pellet, which is spit up. An owl may spit up one pellet in the evening, before it goes hunting. Then, at night’s end, the owl may spit up another pellet.

All birds of prey form pellets. People who study these birds take the pellets apart to learn what they eat.

Nesting

Most species of owls live in wooded areas. A few live in open country, such as farmland and tundra. Owls often keep the same mate for long periods of time. Poor nest builders, they usually make their homes in deserted nests, tree hollows, or crevices between rocks.

Owls lay from one to seven or more eggs, the number depending on the species and the food supply. The slightly elongated eggs are white, off-white, or buff-colored. The female lays one egg every two or three days and begins to sit on them soon after the first is laid. In four or five weeks the eggs start to hatch. By the time the young are three months old, they are able to fly.

Kinds of Owls

The owl order, Strigiformes, consists of the barn owl family, Tytonidae, and the typical owl family, Strigidae.

Barn Owls

In the barn owl family there are 11 species, most of which live in Asia and Africa.

The Common Barn Owl lives in open woodlands in temperate and tropical areas of the world. It is not found in the northern parts of the Northern Hemisphere nor on some Pacific islands. It does not migrate.

This owl is from 15 to 20 inches (38-51 cm) long. It has long, feathered legs and, like other barn owls, has a heart-shaped face. It is sometimes called “monkey-faced owl.” Its plumage is a flecked cinnamon color on the back and off-white on the belly. It lacks ear tufts. Barn owls can catch mice in darkness, locating them by sound. The shrill cries, hisses, and snorelike calls of owls have given many deserted buildings the reputation of being haunted.

The common barn owl is Tyto alba.

Typical Owls

Of the 121 species of typical owls, 18 live in North America. The most common of these owls include the following:

The Screech Owl lives in woodlands from Alaska and Canada south to central Mexico. It ranges in length from 7 to 10 inches (18-25 cm). It is reddish brown or gray with whitish undersides, and has ear tufts on the top of its head. The screech owl is a night hunter and nests in tree cavities. Its call is a tremulous whinny-like whistle.

The screech owl is Otus asio.

The Great Horned Owl lives in woodlands and open country from the tree line in northern Canada and Alaska south to Mexico. It is 20 to 23 inches (51-58 cm) long and has large ear tufts and a white patch on its throat. The feathers are dark brown on the back and lighter with crosswise barring on the belly. This owl hunts mostly at night but is seen abroad in daylight. Its call is a series of deep hoots.

The great horned owl is Bubo virginianus.

The great horned owl has large ear tufts and a white patch on its throat.How Do Owls Start a Family?

The male Great Horned Owl chooses a nesting place. Then he courts a female. He makes special calls, and he performs flying displays. He may offer the female a fresh mouse or other food. He may preen, or comb, her feathers with his beak.

After mating, a female owl usually lays three or four eggs. She sits on the nest and incubates, or warms, the eggs. On her belly, the female has a brood patch. This is a place where the skin is almost bare. It helps her body to warm the eggs directly.

While the female is sitting on the eggs, the male hunts. He finds food for both of them. In some kinds of owls, the male also has a brood patch and helps keep the eggs warm.

How Do Owlets Grow?

When great horned owlets hatch, they are blind and have a thin coat of down—fine, soft feathers. The adult owls feed the owlets every 15 to 20 minutes all night long.

Soon, the owlets have a heavier down coat. They grow strong and active. At 30 days, these owlets can hop about the nest and nearby branches. Gradually, their adult feathers appear. They will fledge, or be ready to fly, between 63 and 70 days after hatching.

Great horned owls bring small prey to the very young chicks. As the owlets grow, their parents offer bigger prey. The owlets quickly learn to tear this prey apart. They stay in the nesting area for several months. During this time, they learn to hunt for themselves, even though their parents continue to feed them.

The Barred Owl, from 17 to 24 inches (43-61 cm) long, lives in wet woodlands east of the Rockies, from Canada south to Central America. This owl has gray-brown plumage with horizontal barring on the neck and vertical barring on the belly. Its back is brown, speckled with white. It has no ear tufts. The barred owl nests in tree cavities or on branches, and hunts at night. Its call consists of two groups of four or five loud hoots.

The barred owl is Strix varia.

The Long-eared Owl lives from Canada southward to northern Mexico, and throughout Europe, Asia, and northern Africa. It may be 13 to 16 inches (33-41 cm) long. This owl has a long ear tuft centered over each eye. It is grayish brown with vertically streaked undersides. The long-eared owl lives in densely branched trees or thickets and is seen only at night. Its call is a low, moaning whoo.

The long-eared owl is Asio otus.

The Short-eared Owl lives in open country and marshes on all continents except Antarctica. For winter, those living in cold regions migrate to warmer climates. This owl is a streaked, tawny-brown color with a short ear tuft centered over each eye, and is from 13 to 17 inches (33-43 cm) long. It hunts during the day and usually nests on the ground. Its call is a bark-like keeyow.

The short-eared owl is Asio flammeus.

Less common species of typical owls found in North America include those listed below.

The Snowy Owl inhabits the Arctic tundra. It is 20 to 27 inches (51-69 cm) long and has white feathers with dark flecks or bars. The long days of Arctic summers have accustomed the snowy owl to hunt by day. Its chief food is the Arctic lemming. When there are food shortages in winter, the snowy owl migrates southward.

The snowy owl is Nyctea scandiaca.

The snowy owl has white feathers with dark flecks or bars.Who Is White As Snow?

Snowy owls are as white as the snow in their home in the far north. These birds of prey live in northern Canada and Alaska, as well as in northern Europe and Asia. Because of their color and their silent flight, their prey may not see or hear them coming.

Snowy owls have especially thick feathers and extra body fat. The feathers and fat help these owls survive in very cold climates. In winter, when food is scarce, a snowy owl may go into a sleeplike state for up to 40 days. It uses very little energy. It needs no food. The owl becomes active again when the weather warms and food is available.

People welcome snowy owls because they kill rats, mice, and other rodents.

The Great Gray Owl, largest of North American owls, lives in northern forest from Alaska to central California. It may reach 33 inches (84 cm) in length. It has a black chin spot and an unusually long tail—about 12 inches (30 cm) long. Its feeding and migratory habits resemble those of the snowy owl.

The great gray owl is Strix nebulosa.

The great gray owl has a black chin spot and is the largest of North American owls.

The Hawk Owl resembles a hawk, not only in appearance but also in manner of flight and in the sound of its call. It is a day hunter of the northern forests. The bird is about 15 to 17 inches (38-45 cm) long and has a dark, mottled brown coloring with white underparts. This owl lacks the keen hearing and silent flight of most other owls.

The hawk owl is Surnia ulula.

The Elf Owl, smallest of North American owls, lives in woodpecker holes in trees and cacti of the southwestern United States and northern Mexico. It is 5 to 6 inches (13-15 cm) long. It hunts for insects at night.

The elf owl is Micrathene whitneyi.

Where Can You Spot an Elf Owl?

An elf owl catches its food with its feet. It eats all kinds of insects, as well as mice, lizards, and spiders. The elf owl sits on a perch, watching. Then it darts out to catch a flying insect. Or, it flies around and scares an insect. Then it catches the insect as it jumps. When feeding owlets, this bird may make a trip a minute, catching and bringing insects to the nest.

Because they eat insects, elf owls are one of a very few kinds of owls that migrate. When winter comes to the United States, the elf owls living there fly south to Mexico. It is warmer in Mexico, so the elf owls there can still find plenty of insects to eat.

The Burrowing Owl lives on prairies in long burrows dug by such animals as prairie dogs and badgers. It is a brown owl, 9 to 11 inches (23-28 cm) long. It hunts by night.

The burrowing owl is Athene cunicularia.

Who Lives in a Burrow?

Burrowing owls nest in underground tunnels. They often borrow homes from prairie dogs or ground squirrels. But if burrowing owls have to—and if the soil is easy to dig—they will use bills and feet to dig their own homes.

A male burrowing owl chooses a burrow and “decorates” it with grass. He performs courtship flights and sings to a female. After mating, the female lays eggs. She then incubates them in the dark nest chamber. The male owl feeds her. Later, both parents feed the chicks. If the owlets sense danger, they make rattling sounds. The rattling scares away such enemies as coyotes and foxes. These animals think the sounds are made by rattlesnakes.

Burrowing owls eat insects that they catch as they fly. They also eat mice, rats, and ground squirrels. They often hunt by sitting on a fence or other low perch to watch for prey.

The Saw-whet Owl, 7 to 8 inches (18-20 cm) long, ranges from southern Alaska to the mountains of Mexico. It hunts for rodents at night. Its whistling call resembles the sound of a saw being whetted (sharpened).

The saw-whet owl is Aegolius acadicus.