Barn Owl
Tyto alba

Context

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Aves
Order: Strigiformes
Family: Tytonidae

Physical Characteristics

About 14-20 inches (35-50 cm) long. Unstreaked white or pale cinnamon plumage on underparts with the back rust colored (Peterson, 1990). The face consists of a heart-shaped facial disc with relatively small dark eyes; the beak is a very pale yellow. There are no ear tufts. The legs are long and slender, covered with narrow feathers. The feet are bristled, with a comb-like middle claw. The sexes appear similar; however, the female is larger and generally darker than the male. With its long wings and buoyant flight, it is almost silent in flight (Burton, 1984).

Habitat

Tyto alba tends to live in woodlands, groves, farms, barns, towns, and cliffs (Peterson, 1990). It prefers to live in open and partly open country, often around humans.

Geographic Range

This species is widely distributed in tropical and temperate zones, including Europe, Africa, southern Asia, and Australia. In the Western Hemisphere, it occurs from southern Canada to Tierro del Fuego (Peterson, 1990).

Diet

The diet of the Common Barn Owl consists primarily of rats and mice. Other small mammals, including small rabbits, are occasionally eaten. Birds, bats, frogs, and large insects supplement the diet when necessary (Burton, 1984).

Reproductive Characteristics

Breeding begins early in the year and lasts until late summer. It tends to take place in buildings, caves, crevices on cliffs, burrows, and hollow trees (American Ornithologists' Union, 1983). Since no nest is built, castings generally form a compact barrier for the eggs; however, baskets or boxes may be used. The nest is usually located on the floor in a dark crevice or hollow. The clutch is normally 3-5 eggs, but may range up to 11, laid at 2- to 3-day intervals. These eggs are white at first, becoming stained yellowish. The female is responsible for most of the incubation, beginning with the first egg; the male feeds the female during this time. Hatching occurs after 33 days. Both parents feed the young (Burton, 19840). The pulli seldom fledge in less than 11 weeks (Fisher & Peterson, 1977).

Remarks

The Common Barn Owl has been divided into 34 geographical races. Fossil evidence suggests an origin 12 million years ago during the Miocene Epoch. T. alba usually is a territorial nocturnal hunter, yet at times it will hunt during the day, flying only a few meters above the surface (Burton, 1984). The voice has been described as a shrill rasping hiss or snore (kschh or shiiish). There may also be an eerie screech that is long and drawn out (Peterson, 1990). In flight, the voice may be more of a get-get (Burton, 1984).

In common with other owls, undigested fur and bone is regurgitated as castings ("owl pellets"), rather than being passed through the complete digestive system.

American Ornithologists' Union. 1983. Check-list of North American birds, 6th ed. Allen Press, Lawrence, 877 pp.

Burton, J. A. 1984. Owls of the world: their evolution, structure and ecology.Tanager Books, Dover, 208 pp.

Fisher, J., and R. T. Peterson. 1977. World of birds. Crescent Books, New York, 191 pp.

Peterson, R. T. 1990. A field guide to western birds. Houghton Mifflin Company, Boston, 432 pp.

Mary Kirschenbaum, July 1996.