Barn Owl (Tyto alba)
The Barn Owl is a pale, long-winged, long-legged owl with a short squarish tail. Depending on subspecies, it measures about 25–45 cm (9.8–18 in) in overall length, with a wingspan of some 75–110 cm (30–43 in). Tail shape is a way of distinguishing the Barn Owl from true owls when seen in flight, as are the wavering motions and the open dangling feathered legs. The light face with its heart shape and the black eyes give the flying bird an odd and startling appearance, like a flat mask with oversized oblique black eyeslits, the ridge of feathers above the bill somewhat resembling a nose.
Its head and upper body typically vary between a light brown and a dark grey (especially on the forehead and back) feathers in most subspecies. Some are purer, richer brown instead, and all have fine black-and-white speckles except on the remiges and rectrices, which are light brown with darker bands. The heart-shaped face is usually bright white, but in some subspecies it is browner. The underparts (including the tarsometatarsus feathers) vary from white to reddish buff among the subspecies, and are either mostly unpatterned or bear a varying amount of tiny blackish-brown speckles. It was found that at least in the continental European populations, females with more spotting are healthier on average. This does not hold true for European males by contrast, where the spotting varies according to subspecies. The bill varies from pale horn to dark buff, corresponding to the general plumage hue. The iris is blackish brown. The toes, as the bill, vary in color; their color ranges from pinkish to dark pinkish-grey. The talons are black.
Contrary to popular belief, it does not hoot (such calls are made by typical owls, like the Tawny Owl or other Strix). It instead produces the characteristic shree scream, ear-shattering at close range. Males in courtship give a shrill twitter. It can hiss like a snake to scare away intruders, and when captured or cornered, it throws itself on its back and flails with sharp-taloned feet, making for an effective defense. Also given in such situations is a rasp and a clicking snap, produced by the bill or possibly the tongue. It is most recognizable by its “mask-like” face.
It hunts by flying low and slowly over an area of open ground, hovering over spots that conceal potential prey. They may also use fence posts or other lookouts to ambush prey. The Barn Owl feeds primarily on small vertebrates, particularly rodents. Studies have shown that an individual Barn Owl may eat one or more rodents per night; a nesting pair and their young can eat more than 1,000 rodents per year.
The Barn Owl has acute hearing, with ears placed asymmetrically for improved detection of sound position and distance, and it does not require sight to hunt. Hunting nocturnally or crepuscularly, it can target and dive down, penetrating its talons through snow, grass or brush to seize rodents with deadly accuracy.
Barn Owls are relatively common throughout most of their range and not considered globally threatened. However, locally severe declines from organochlorine (e.g. DDT) poisoning in the mid-20th century and rodenticides in the late 20th century have affected some populations. While the Barn Owl is prolific and able to recover from short-term population decreases, they are not as common in some places as they used to be. The most 1995-1997 survey put their British population at between 3,000 to 5,000 breeding pairs, out of an average of about 150,000 pairs (varying with rodent stocks) in the whole of Europe, for example. In the USA, Barn Owls are listed as endangered species in seven Midwestern states, and in the European Community they are considered a Species of European Concern.
Unusual for such a good-sized and carnivorous animal, the Barn Owl emphasizes r-selection (as does their prey). Most individuals manage to breed only once in their life, falling victim to predators or accidents before being 2 years of age. While wild Barn Owls are thus decidedly short-lived, the actual longevity of the species is much higher – captive individuals may reach 20 years or more’