Barn Owls: Tytonidae

Physical characteristics: Sometimes called simply the barn owl, this species is widely distributed. Populations in different locations can be quite different in size and appearance. They range in length from 11 to 17 inches (29 to 44 centimeters) and vary in weight from
0.4 to 1.5 pounds (0.2 to 0.7 kilograms). The North American subspecies is the largest. The feathers are subtly colored but quite beautiful seen up close. They are mottled gray and buff-brown on the back and pale on the belly, with fine spots overall. Members of island populations tend to be darker in color than mainland populations. Males and females look alike.

Geographic range: This is the most widely distributed owl species. Barn owls occur on every continent except Antarctica.

Habitat: Barn owls prefer areas of open woods, grasslands, and brushy areas. Areas near cliffs offer nest sites. They will live near Young barn owls learn to preen, using their bill to straighten and clean their feathers. (Jane Burton/Bruce Coleman Inc. Reproduced by permission.) humans on farms or in urban areas as long as there are nest sites (for example, barns, silos, or church steeples) and open space for hunting.

Diet: Barn owls take whatever prey is available, the right size, and active at night. They seem to choose the slowest and fattest species among all the possible prey, usually specializing in small rodents such as voles, mice, and shrews. Small birds, amphibians, reptiles, and fish are occasionally taken, and invertebrates such as insects are rarely eaten.

Though most owls are "sit and wait" predators, barn owls often hunt by flying low and slow over open ground. They use their sense of hearing more than sight to locate prey. They usually hunt alone, but if prey is plentiful, they may hunt in groups.

Barn owls are monogamous (muh-NAH-guh-mus). At the beginning of the breeding season, males make courtship flights, patrolling their territories while calling loudly. Sometimes a male and female will fly together, or the male will chase the female while both scream loudly. One courtship display is the moth flight. The male hovers in mid air in front of a female. Another is the in-and-out flight. The male flies into and out of the nest sight as if showing it off. The female shows her interest with a snoring call, and the male responds with a gift of food.

Barn owls adjust their nesting efforts to the amount of prey that is available. If food is plentiful, the female lays a large number of eggs and may even nest a second time in the same year. She lays one egg every two or three days till the clutch is complete but starts incubating the eggs right away. This means the first owlet may hatch two to three weeks before the last. Young owls leave the nest when they are fifty-six to sixty-two days old. A female may start to lay more eggs before the last owlet from her first clutch has fledged.

Barn owls and people: One nickname for the common barn owl is monkey-faced owl. Some people actually believed they were flying monkeys. Barn owls have been introduced to some islands as a form of natural pest control. Grape growers in California are among the farmers that now welcome barn owls to their properties by hanging up nesting boxes. The owls help to control rodent pests.

Conservation status: Barn owls in North America have been declining slightly in numbers for the past four decades. Similar small declines are documented in Canada, Britain and Europe. So far, wildlife experts are not concerned that the species is threatened. ∎