Barn Owls
By
Eileen Berger Indian Trail Master Naturalist
You might have been driving on a country road late at night only to be surprised by a large bird suddenly flying across the road in front of your car. If so, it was probably an owl swooping down to catch its prey. We know that owls are mostly active at night, roosting in the daytime well camouflaged by their coloration. Owls are classified into two families, Tytonidae, the barn owls, and Strigidae, called typical owls. Worldwide there are 15 species of barn owls, with one, Tyto alba, found in North America.
Unlike many bird species, the female barn owl is more highly colored than the male, with reddish and more heavily spotted chest. The female is darker overall, while the male is paler. They have a heart-shaped face with dark eyes. They range from 12 to 16 inches with a wingspan of 39 to 49 inches. Like all owls, they have fluffy plumage which lets them fly without making a sound. They do not have the characteristic “who” call we associate with owls, but an eerie, raspy sound. They live year round in their range and may roost in the nesting area.
All owls have excellent low-light vision with front-facing eyes which are fixed and cannot rotate. However, their necks have many more vertebra than humans have, and they are able to rotate their heads 270 degrees. The barn owl has been found to have the best hearing of any animal that has ever been tested. It can catch mice in total darkness. It has a dish-shaped face with a ruff of feathers that funnel the sounds to the ears. The owl’s ears are not placed symmetrically on the side of the head, but at two different positions, one higher than the other. This allows the bird to triangulate the sounds coming into each ear and determine the exact position of the prey.
The barn owl got its name from the places it chooses to nest. It lives in open habitats such as grasslands, deserts, marshes, agricultural fields, ranchlands, and even towns and cities. It will nest in tree cavities, cliff edges, caves, sports stadiums, church steeples, drive-in movie screens, houses, barns, and even nest boxes. The female makes a nest of her own pellets, which are regurgitated remains of prey with fur and bones. She shreds them with her feet to make a cup, into which she may lay from 2 to 18 eggs. The chicks hatch in 29 to 34 days, and will fledge, or leave the nest, after 50 to 55 days. The female can have from one to three broods a year. Barn owls have a long breeding season and may nest any month of the year.
Barn owl populations are declining, probably due to loss of nesting sites, use of DDT and the pesticides used to kill rodents, which are its main food source. They swoop low across fields at night when they are hunting, and are often hit by cars. Since they will nest in an appropriately-sized nest box, providing nest boxes could help them recover. For information about barn owls or any other species, check out the fascinating website from Cornell Lab of Ornithology www.allaboutbirds.org.