Barn Owl

The western barn owl is a medium-sized, pale owl native to Europe, southwestern Asia and Africa, with long wings, a short squarish tail and a large, heart-shaped facial disc. It does not hoot but gives an eerie, drawn-out screech. It is nocturnal over most of its range, though in Great Britain it also hunts by day. Nearly all of its food is small mammals taken from the ground, which it locates by sound with very acute hearing. The pair usually mate for life, and a clutch averaging about four eggs is laid in a hollow tree, old building or cliff fissure. Compared with other owls of similar size, it has a much higher metabolic rate and needs relatively more food.

About the barn owl

The barn owl is a medium-sized, pale owl with long wings, a short tail and a white, heart-shaped face, in the owl family Tytonidae. Barn owls in the Americas belong to the American barn owl group, Tyto furcata, which ranges from North to South America; most taxonomic authorities treat it as part of one worldwide barn owl species.

That split is a matter of taxonomy rather than looks. Most taxonomic authorities recognize a single barn owl found on every continent except Antarctica, made up of the western, American and eastern barn owl groups and sometimes the Andaman masked owl. A few, including the International Ornithologists' Union, separate these into distinct species. Under that split, the American birds are Tyto furcata and the name Tyto alba is kept for the western barn owl of Europe, southwestern Asia and Africa.

The barn owl has long wings, a short, squarish tail and long legs sparsely feathered down to grey toes, with no ear tufts on its large, rounded head. The head and back are pale brown to grey with fine black-and-white speckles, and the underparts range from white to reddish buff. Seen in flight, the flat white face with oversized black eye slits looks almost like a mask.

Females are larger and usually more heavily spotted than males. Typical weights are around 570 g (20 oz) for females and 470 g (17 oz) for males, and body lengths of 34–40 cm (13–16 in) for females against 32–38 cm (12.6–15 in) for males.

The bird is built for silence. Tiny serrations on the leading edges of the flight feathers and a hairlike fringe on the trailing edges break up airflow over the wing, cutting the noise of each wingbeat. Soft, hairlike extensions on the feathers dampen sound further.

Behavior and diet

Like most owls, the barn owl is nocturnal, often becoming active shortly before dusk. They hunt by flying slowly and low over open ground, hovering over spots that might hide prey, or watching from fence posts and branches. Their ears sit at different heights on each side of the head, and this asymmetry lets them pinpoint both the direction and distance of a sound. Their ability to locate prey by sound is the most accurate of any animal tested.

The heart-shaped facial disc plays a part in this. Experiments show that without its ruff feathers, a barn owl can still tell where a sound is coming from left to right but loses its sense of height. Hunting crepuscularly or in full dark, it can drop onto prey and drive its talons through grass, brush or snow.

Small mammals dominate the menu. In the United States, rodents and other small mammals usually make up about 95% of the diet, with voles the top prey in North America and shrews second. A single owl may eat one or more voles a night, roughly 23% of its body weight. Small prey is eaten whole, fur and bones included, and the indigestible parts come back up later as pellets. Birds, bats, lizards, frogs and insects are taken where they are common, but barn owls do not regularly eat domestic animals.

Because they eat so many rodents, barn owls are valued by farmers, who often find them more effective than poison. Excess prey is cached at roost sites for lean times. When disturbed, a barn owl lowers its head and sways it from side to side, hisses and snaps its beak.

Barn owls usually pair for life. They nest in cavities such as hollow trees, cliff crevices, barn lofts, church steeples and nest boxes, and they add no nesting material. As the female incubates, she pulls in the dry fur from her own pellets, so the chicks hatch onto a carpet of shredded pellets. In North America, most nesting happens between March and June. Incubation lasts about 30 days, chicks fledge at about nine weeks, and they depend on their parents until about 13 weeks old.

Range and habitat

The American barn owl is native to North and South America and has been introduced to Hawaii, where it was released on Kauai to control rodents and has also been found to eat native birds. In North America it ranges as far north as the northern United States and southwestern British Columbia. Most birds stay put year-round, though some in the north migrate.

This is a bird of open country: farmland, grassland and rough pasture with some scattered woodland, usually below 2,000 m (6,600 ft), though it can reach 3,000 m (9,800 ft) in the tropics. It likes to hunt along woodland edges and rough grass strips beside pasture. The supply of suitable nest cavities often limits how many barn owls an area can hold.

Young birds in the United States usually disperse 80–320 km (50–199 mi) from where they hatched, and the farthest recorded travelers ended up about 1,760 km (1,094 mi) away. A New Jersey study found an average home range of 7.17 km² (2.8 sq mi).

Conservation status

The barn owl is rated Least Concern on the IUCN Red List in BirdLife International's 2019 assessment, which treats the barn owls of the world as one species, Tyto alba. It is also listed in CITES Appendix II.

Barn owls are relatively common across most of their range and are not considered globally threatened. Even so, many areas of the United States have seen declines, with the Midwest hit hardest. DDT and other organochlorine poisoning in the mid-20th century and rodenticides later in the century hurt some populations, especially in North America.

Habitat loss is probably the most damaging factor today, as the rough grassland barn owls hunt over is cleared for intensive farming. Vehicle collisions, power lines, rodenticides and predation by great horned owls also slow recovery. Nest boxes under the eaves of buildings and elsewhere can boost local numbers, and they may reduce the need for rodent poison.