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Wisconsin Natural Resources magazine

Wisconsin Natural Resources magazine

With ears of slightly different sizes, one of which is located a little higher on the head than the other, barn owls can sense direction and distance with incredible accuracy. © Steven Servantez

April 2005

Stealth on silent wings

Barn owls' deadly accurate nighttime flights are an
all too rare sight.

Ann Bailey Dunn

With ears of slightly different sizes, barn owls can sense direction and distance with incredible accuracy. © Steven Servantez

The Common Barn Owl is one of Wisconsin's rare birds, a remarkable bird of prey that can silently, accurately find its way and capture prey in total darkness.

The barn owl can turn its head more than 270 degrees, almost completely around, in order to see its surroundings. Its fearless brown eyes are fixed within the sockets and are as large as a human's. Extremely large retinas give the barn owl binocular vision that is from 50 to 100 times more efficient than human sight at distinguishing small objects in dull light. Sharp vision is matched by unequaled hearing. The barn owl's ears lie under its round facial disks. Its ears are slightly different sizes and one is located a little higher on the head than the other. This asymmetrical placement enables barn owls to sense direction and distance with incredible accuracy. This owl can detect a mouse stepping on a dead leaf from over 75 feet away. Its dinner menu includes mice, shrews, moles, rats, birds, frogs, insects, lizards, bats and baby rabbits.

A creature of the night, the barn owl's unmistakable high-pitched screeches and eerie hiss-screams are occasionally heard throughout the southern third of the state. On a still night its calls travel for miles.

For centuries barn owls were victims of naive superstition and they were driven from their nests in the mistaken belief that they brought bad luck. In fact, these sleek, silent fliers are wonderful mousers. These crow-sized birds measure about 13 to 15 inches in length and weighing from 17 to 20 ounces. These flying mousetraps can eat 1.5 times their weight each day in mice and meadow voles!

The barn owl is handsome, dressed in a sandy brown, golden and cinnamon suit of feathers streaked with white and blue with a white belly speckled black or brown. The barn owl is distinguished by a large, round tuftless head and a white heart-shaped face edged brown. At night it appears completely white. Its look and moth-like flight earned the nickname ghost owl.

Barn owl flight is silent as a stalking cat. Special feathers on the front of its 42 to 45-inch wings dampen noise. It attacks with frightening efficiency; gripping and snatching prey with razor-sharp talons. A barn owl seldom misses its mark while cruising the edge of open country along meadows, grasslands, fencerows and wetlands near granaries and barns. Small quarry is swallowed whole. Larger victims are torn into pieces with a sharp, hooked beak.

Though these owls can breed year-round in Wisconsin, mating typically takes place from April through July. If food is plentiful, a second brood may be reared in early fall. Courtship consists of the male chasing the female, bringing her mice and uttering a series of rapid squeaking noises. It's believed that barn owls mate for life. As cavity nesters, the pair chooses natural sites or abandoned buildings, church steeples, silos, belfries, water towers, manmade nesting boxes as well as barns. A pair may use the same nesting site each year.

The female lays one white egg every two days until there are five to seven in her clutch. Both parents bring prey to the young, called owlets. The food, usually mice, is swallowed whole. A nesting pair of barn owls with six young may consume over 1,000 mice during their three-month nesting period.

Barn owls are not equipped to survive severe winter weather and, truth is, they have never been plentiful in Wisconsin. Their bodies store little fat. If they don't find a constant food supply, especially during cold spells, they may die. On average a barn owl lives only three to four years.

The Common Barn Owl, Tyto alba, (Tyto is Greek for owl and alba is Latin meaning white) is also known as monkey-faced owl, ghost owl, rat owl, night owl and death owl. It is listed as a state endangered species in Wisconsin due to habitat loss from more row cropping, fewer fields of oats, fewer fencerows and wetlands. Metal pole barns with fewer uncovered entryways also reduced rural nesting areas.

Owls are protected by the Migratory Bird Treaty Act, meaning it is illegal to harm or possess these raptors. If you find an owl that appears wounded or poisoned, call your local conservation warden who often works with networks of licensed rehabilitators who can help injured birds recover.

Support to the Endangered Resources Fund could help train volunteers to build and install barn owl boxes and resume programs to track barn owl movements and captive breeding.

Ann Bailey Dunn writes from Campton, Kentucky.