Facts about the Common Barn Owl HABITAT:
Barn Owls are found throughout North America and adapt well to living in close proximity to humans. They are usually found in warmer, drier climates. On the Palouse, they thrive in the summer but are at the edge of their winter range. Their thinner layer of feathers and long, un-feathered toes and legs leave them susceptible to cold temperatures and they often have difficulty with Pullman winters. Many will not survive if the weather remains very cold for long, particularly if a heavy snow cover protects their primary prey (mice).
HUNTING & DIET:
The majority of their diet consists of small rodents. They are quite particular to this prey source and often will not take other food, even when faced with starvation. Growing Barn Owls can eat 4 to 6 mice per bird each night and it is not uncommon for a pair to raise 4 – 5 young to fledging. Since adults also need 2 to 3 mice for themselves each night, a single Barn Owl can hunt upwards of 30 mice in one night! While working so hard to feed their young, these owls are very valuable for keeping rodent populations in check.
One of the most impressive aspects of Barn Owls is that they can hunt in total darkness. They can do this not with echolocation, but instead with acoustic prey location called triangulation.
FACIAL DISCS AND HEARING:
Their excellent hearing is what these owls depend on. As with some other species of owls, Barn Owl ears are slightly offset from one another. Their left ear is higher up than their right ear. This off-set design helps the owl to hear in 3D. They are also one of a few owls to have a small external ear flap (pinna) in front of their ear holes, which help the owl pinpoint exactly where a sound is coming from, even if it is behind them. Their large facial disk is actually two in one (one for each ear around each eye). These structures act like amplifiers and aid in capturing sound. Their bill is pointed downward to help maximize the surface area of these disks.
MALES V FEMALES:
Barn Owls are light to medium brown on their back and wings, white on the chest and under the wings, and spotted all over. There tends to be a small amount of sexual dimorphism between males and females with females having slightly darker plumage with more spotting on their chests and under their wings.
MATING & NESTS:
Barn owls, of course, do nest in barns. But in the absence of a barn, they may choose any cavity or cave-like location to nest in.
Another unique owl characteristic is that the front edges of their primary flight feathers are serrated like a bread knife. This breaks up air turbulence and allows them to fly almost completely silently. There are two purposes for this – for one, owls do not want their prey to hear them coming. The second reason is that owls depend so much on their hearing that any noise from their wings would hinder their hunting ability.
Owls also have unique feet relative to most other raptors. Instead of standing with three toes in front and one toe pointing backwards (known as the anisodactyl arrangement), they stand with two toes forward, and two pointing backwards (known as a zygodactyl arrangement). However, while hunting, owls have the ability to rotate their third toe forward into an anisodactyl arrangement.
Another characteristic of owls is the large size of their eyes. They are so large, in fact, that there is no space for extrinsic muscles to move the eyes. As a result, there is a bony ring around each eye that fixes them in place. While humans and most mammals can look to the left and right with their eyes without turning the head, owls cannot. To compensate for the lack of eye movement, owls have twice as many vertebrae in their neck as mammals – we have 7, they have 14. This allows them to turn their head completely backwards and then over the opposite shoulder. While they cannot rotate their head 360 degrees in each direction as many people believe, they can rotate it about 270 degrees each way. Because of the large number of vertebrae, owls can also extend their neck up to look taller and thus more imposing to any predators.
While most owls are members of the Strigidae family (great horned owls, screech owls, great grey owls, etc.), barn owls are part of the Tytonidae family. There are about 16 species of Tyto owls, but the Common Barn Owl is the only one found in North America. They are unique anatomically in that they have a grooming talon, or pectinate claw. This talon has a comb-like ridge along its edge, which the bird uses for grooming. Tyto owls also have the split, heart-shaped facial disk.
Barn Owls have the greatest number of vocalizations of all our owls, but most are quiet noises made at the nest. The sounds you are most likely to hear include hisses, screeches, and bill-clapping though they also twitter softly, coo, and chirp.
Also sometimes called the Ghost Owl, Barn Owls have often been considered the ghosts of haunted houses, barns, and old castles. Their nocturnal habits, silent flight, white underside, and eerie screeches can easily conjure up the impression of a ghost surveying its domain.