All About Owls

Owls are soft-plumaged, short-tailed, big-headed, usually nocturnal birds of prey. There are about 132 species of owls divided into two families: the Barn owls – Tytonidae, and the typical owls – Strigidae. Common barn owls (Tyto alba) have an almost world-wide range. Most of the black-eyed Wood owls, Strix, have feathered feet and rounded wings. Wood owls are found chiefly in temperate woodlands in the New and Old Worlds.

Legends claim that owls are wise and can predict births, deaths and other significant events. An owl near a house was considered a sign of bad luck. Associating owls with misfortune may have been because they are nocturnal hunters and night is often associated with evil.

Most of an owl’s behaviour is instinctive, though it has the capacity to remember and the ability to learn new habits for a limited number of novel situations. Owls remember the localities where they were successful in finding prey, but they will often return to those places for some time after the prey supply has been exhausted.

Owls have big eyes, located at the front of the head, allowing for 3-dimensional vision, which is vital in judging the distance and size of a moving target. Very wide corneas allow the maximum of light through to the retina. Although their eyes are fixed in their sockets, owls can track moving targets by turning their heads upside down and nearly all the way around. This is the reason behind the myth that an owl will turn its head far enough to wring its own neck if a person walks around it in circles.

An owl’s flight is silent. The flight feathers on the wings are fringed, which muffles the noise of air passing through. They can, therefore, approach their prey without detection.

Owls hunt and eat rodents and other small mammals, such as birds, snakes, lizards, frogs, insects and fish. Larger species will hunt larger prey; Europe’s eagle owl and the great horned owl of the Americas are capable of capturing skunks and cats.

Owls have hooked beaks, stout legs and long talons. They capture prey with their feet and then drive their claws into their victims. Sometimes the victim then receives a lethal bite from the beak. The owl’s claws and beak are in proportion to the size of its prey. Usually the prey is swallowed whole. Any indigestible matter is compressed into oval pellets and regurgitated the next day. These pellets are often found beneath roosting perches and provide a record of the bird’s diet.

Some species rely on hearing to hunt on the darkest nights. The ears are extremely sensitive and are hidden among feathers behind the eyes. What looks like ears on some owls are simply tufts of feathers. It is believed that their hearing is about ten times better than humans. The facial disks are thought to have an acoustical function of gathering and concentrating sound waves.

Vocal signals are more important to owls than visual ones. Their large vocabulary of sounds include hoots, whistles, shrieks, screams, chatters, laughs and growls. Clicking the beak of clapping the wings also produces sounds. Different species have different calls.

Most owls go to sleep as the sun rises. They rest in deep shade on large branches near the trunk of the tree or in holes in the tree. Their colour and posture often make them look like tree shrubs or large pieces of bark.

While most owls are nighttime hunters, a few do most of their hunting by day. Many will also hunt in daylight hours if food is scarce or if they have a large brood to feed.

One of an owl’s most classic defenses against predators is a threatening pose with its head lowered and the wings and tail fanned out. The glaring eyes, bobbing head and fluffed feathers make the owl look larger than it actually is. Sometimes it will snap its bill to draw attention to its powerful beak. It will also act as a decoy to draw predators away from its young. In its natural habitat, camouflage also helps to protect many owls from being seen by predators.

Owls are truly unique birds. Their keen sensory perception enables them to be efficient nocturnal predators. Their body structure is equally adapted to that of the soaring seagull.

Owls need to proclaim their hunting territories and communicate with their own mates over large areas, and the carrying power of low-pitched notes is much greater than that of high-pitched or squeaky ones. The majority have low-frequency voices, giving them a human-like quality and their hoots and screams make up a well-developed language. Owl hoots, therefore, act rather like foghorns, as sound beacons in the darkness.

Owls found in North America
Barred Owl	Ferruginous Pygmy Owl	Saw-Whet Owl
Boreal Owl	Flammulated Owl	Short-Eared Owl
Burrowing Owl	Great Gray Owl	Snowy Owl
Common Barn Owl	Great Horned Owl	Spotted Owl
Eastern Screech Owl	Long-Eared Owl	Western Screech Owl
Elf Owl	Northern Hawk Owl	Whiskered Owl
	Northern Pygmy Owl