Barn Owl - Tyto alba

The Barn Owl is a resident bird that is often seen after dusk, caught in the headlights of cars that make it look pure white in colour and giving it a ghostlike appearance as it hunts at the roadside in farmland areas where there are hedgerows and copses.

Habitat

Favoured habitats include old barns, ruins and exposed buildings on farmland, on the outskirts of villages and in some cases open woodlands. Their ideal hunting habitat is rough grassland such as field edges and grass strips which supports good populations of small mammals, especially voles. Set-aside provides valuable hunting areas in this way.

Description

The Barn Owl has large black eyes, pure white underparts, and light golden upperparts with light grey flecks. Its facial disc (face area edged by conspicuous feathers) is pale and heart-shaped, the feathers around the edge of the facial disc are stiff helping to funnel sound into the owls sensitive ears; the ears are placed asymmetrically to enable the Barn Owl to pinpoint its prey with precision. It is long-winged with a wingspan of 80-95cm; and long-legged growing to 33-39cm in length. The talons are the Barn Owls principal hunting weapon, the outer toe on each foot is reversible which helps when capturing the prey and keeping a grip whilst in flight. It is a silent flier, and often has its feet dangling!

Biology

Voles, mice, frogs and insects make up most of the Barn Owls diet, which it locates using its acute sense of hearing (they can often find their prey by sound alone), and this is when it’s most likely to be seen while hunting at dawn or dusk and can be heard making it’s eerie screeching noises! Prey is swallowed whole with the indigestible parts (e.g. bones and fur) regurgitated in dark coloured pellets that are found at favoured roosting sites. The pellets are a good way of knowing where Barn Owls are, they can be soaked in warm water to break them down and see what the Barn Owl has been eating.

Once the Barn Owl has pinpointed prey it starts to hover by bringing it wings forward and tail down; this takes a lot of energy so it attacks swiftly. By lifting its wings it drops silently out of the sky still keeping track of its prey, bringing its talons forward the owl grabs its prey. Taking the prey in either its mouth or talons the owl heads to a favourite perch to consume its prey.

In late April onwards nests are built in tree holes, ruined buildings, farm buildings, and particularly barns. The age of the young is staggered as eggs are laid at two to three day intervals, and as soon as the first egg is laid the female starts incubating, this means the young hatch at intervals. The female is fed by the male while she incubates the eggs; once they hatch she will continue to be fed by the male who will also be feeding the chicks, once the chicks have a covering of down the can retain body heat and the female will help with the hunting. If there is a shortage of prey available the youngest chicks may starve as their older siblings out-compete them for the available food supply. The young produce a loud hissing call encouraging their parents to bring them food; it has been described as snoring! The young remain in the nest for 8-10 weeks, for the next couple of weeks the young will remain in the parents’ territory after which they will be encouraged to leave and find their own.

Autumn is a particular good time for spotting Barn Owls. They can be seen throughout the year but during the breeding season sightings of Barn Owls are fleeting with only quick glimpses of adult birds as they catch prey and disappear back to their nest site to feed the young; come autumn the adults only have themselves to feed, also the juveniles have just fledged and are honing their hunting skills. With dusk falling earlier the owls are active earlier; autumn is also when the population of short-tailed voles is at its peak which is one of the most important prey species for the Barn Owl.

Threats

From the late 1800’s onwards the numbers of Barn Owls underwent a decline, this is due to a combination of effects from traffic deaths, loss of habitat from the destruction of their hunting and nesting sites, use of pesticides and more intensive farming practices. This would have been made worse with the loss off traditional roosting sites of old trees and old farm buildings which have been converted for other uses. Rodenticides also have an impact as Barn Owls feeding on rodents that have eaten poisoned bait can themselves become poisoned.

Conservation

The Barn Owl is specially protected under schedules 1 and 9 of the Wildlife and Countryside Act (1981) making it illegal to kill, injure or take a Barn Owl or to remove or damage eggs. It is also included in the Birds of Conservation Amber List, and is listed as a Species of Concern in the UK BAP (Biodiversity Action Plan) and a key species in the Wiltshire BAP.