By Abbie Young
The barn owl is one of the most abundant and widely distributed owl species in the world, inhabiting every continent except for Antarctica. Unfortunately, in Georgia it’s also an owl in decline and listed in the State Wildlife Action Plan as a species of concern. (More on that in a minute, including how you can help.)
Barn owls are easily distinguished from other owls by their pale, heart-shaped facial disk. The bird’s underside is typically white or light gray, while the head, back and upper wings are normally tan and mottled with gray and black.
Unlike other species of owls found in Georgia, the barn owl communicates through a variety of screeches, hisses and physical displays (listen). As a rodent specialist, it primarily eats mice, rats and voles.
Barn owls are found in rural and urban areas, and prefer to nest in tree cavities, caves and human-made structures such as church belfries and barn lofts. The birds are primarily monogamous and have been known to return to the same nesting site year after year if the site has not been significantly changed. Unlike Georgia’s other owl species, which usually nest during the winter and early spring, barn owls can nest at any time of the year. The timing usually closely coincides with high food abundance.
The owls normally fledge only one clutch a year. The clutch size varies from two to nine eggs, with five being the average. Surviving young stay in the nest until they begin to fledge at 12-13 weeks. On average, barn owls live three to four years.
A variety of factors have caused barn owls in Georgia to become uncommon to rare in areas where they were once abundant. The number one threat the species faces is habitat loss. Intense row-crop agriculture, the loss of natural grasslands and fewer large trees with suitable nesting cavities has led to sharp population reductions. The increased use of rodenticides on farms and in neighborhoods has likely resulted in some owls being inadvertently poisoned. Barn owls are also frequently killed in collisions with vehicles due to the birds’ habit of flying close to the ground.
One way to help barn owls rebound is by placing nest boxes in areas where the population has declined. Here are instructions for building a nest box.
In choosing a nest box site, habitat is the key to increasing the chances you attract a breeding pair. Nest boxes are best placed in habitat consisting of a mixture of open fields, marshes and grasslands, or on the edges of sparse woodlands. Areas where rodents are abundant also answer the owls’ preference to nest close to a reliable food source. The interior of abandoned barns and other structures are favorable spots if those buildings are not near roads and other areas of high human activity. Avoid mounting a nest box on the outside of a building unless there is not a better alternative.
Nest boxes can also be secured to a tree or mounted on one or more poles in an open field. Metal poles are recommended, because wood can rot over time. If wood poles are used, they should be at least 6-by-6 inches and set in concrete. A predator guard, which physically impedes mammalian and reptile predators from climbing to the nest box, should be placed several feet above ground – and below the box – on the tree or pole. The guard will reduce the chances a snake, raccoon or other predator can reach the nest and eat the eggs or young.
Place boxes 15 feet up or higher, with the opening facing suitable hunting habitat. If adding more than one nest box in an area, keep the boxes at least 100-200 yards apart. If barn owls use a nest box, clean the box once a year after the owlets have fledged or the nest has failed. (Barred owls – a more common species in Georgia – will also use a barn owl nest box, especially if it’s mounted to a pole or tree.)
Anyone who knows where barn owls are nesting is encouraged to report the location and details to Georgia DNR’s Wildlife Conservation Section, by email or phone (478-994-1438).
Abbie Young is an administrative assistant with DNR’s Wildlife Conservation Section in Forsyth. She previously worked as a naturalist with the DNR State Parks and Historic Sites Division.