The Barn Owl (Tyto alba) is a nocturnal raptor belonging to the Tytonidea family and the Strigiformes order. Its distribution is cosmopolitan, spanning various regions including Europe (except the far north), Southeast Asia, Africa, and North America up to the border with Canada, South America, and Australia. The Barn Owl inhabits open habitats such as bare barren landscapes, fields, plains, and sparse and deciduous forests, and is common in residential areas, especially agricultural regions.

A prominent characteristic of the Barn Owl is its facial bouquet, made of small, dark feathers that connect down from the beak. This bouquet, set against the small and dense white facial feathers, creates a heart shape. Females are usually more striped than males on their belly and lower body parts. In contrast to the light belly, the upper parts of the body are dark with a golden-brown-reddish color dotted with dark gray and white spots. The female Barn Owl is heavier than the male, with an average weight of 360 grams compared to the male’s average weight of about 310 grams. Despite the difference in body weight, the wingspan is similar, ranging from 265-309 millimeters. The Barn Owl’s wings are rounded and relatively long along its body. Its legs are long and covered with feathers, with a comb on the claw of the second finger. The fourth finger can move backward, aiding in grasping prey. The claws are strong and curved.

The Barn Owl is adapted to nocturnal activity: its eyes are located at the front of the head, allowing for three-dimensional (stereoscopic) vision. Each eye covers about 70% of the field of vision, and combined, the total field of vision reaches 110 degrees. This three-dimensional vision enables the Barn Owl to accurately estimate the distance to its prey. Since the eyes are fixed inside the eye sockets to maintain a sharp and focused image, the Barn Owl must turn its head to change its view. Indeed, the Barn Owl’s neck can rotate up to 180 degrees, and the internal structure of the eye provides it with high sensitivity to light.

The Barn Owl’s sense of hearing is highly developed, with asymmetrical ears differing in size and direction. A fold of skin forms a kind of auricle, which can move to seal its ears while at rest. This unique ear structure allows the Barn Owl to locate sounds both horizontally (azimuth) and vertically (elevation) with great precision, enabling it to quickly and accurately pinpoint its prey. Studies have shown that the Barn Owl perceives sounds in a frequency range of 200 to 10,000 Hz. The differences in sound reception time and intensity between the two ears, resulting from their asymmetry, allow the Barn Owl to accurately locate sounds in space. The arrangement of facial feathers helps concentrate sound waves to the ears.

The Barn Owl is inaudible when hunting due to its soft plumage and the comb-like serrated edges of its flight feathers. Hunting typically occurs during the hours of darkness. The Barn Owl employs two hunting methods: one involves standing at an observation point, using sight and hearing to locate rodents before diving and capturing them. The second method involves flying low in a silent and light manner, listening for prey, and then diving to capture it. Just before striking, the Barn Owl changes its body position: it sends its legs forward, pulls its wings and the head back, and closes its eyes. It then uses its strong claws to grasp the prey, biting the back of its neck to ensure it is dead. The prey is carried either by the legs or mouth to a feeding spot, where it is swallowed whole and digested in the stomach. Undigested parts (hair, bones, claws, etc.) are expelled through the mouth as a pellet, whose shape corresponds to the physical structure of the stomach. The number of pellets emitted per day depends on the amount of food eaten, but usually, 1-3 pellets are produced daily.

The Barn Owl has a roosting site where it stays for most of the year, as well as a nesting site where it stays during the nesting season. The Barn Owl usually nests in fixed places to which it returns every year. Since it does not build a nest, it uses existing places such as water holes, abandoned buildings, and attics. The relationship between a mated pair is maintained for a time, sometimes for their entire lives. The nesting season of the Barn Owl, which typically has one nesting cycle, extends from the end of February to July.

In the “year of voles” (a year with an abnormal increase in their population), Barn Owls can have two or even three nesting cycles, extending the nesting season until September. In the interior valleys, however, the second nesting cycle often does not conclude successfully due to the heavy heat. The Barn Owl lays an average of five eggs. During the “year of voles,” when food is abundant, clutch size increases. The first chick hatches after 28-30 days, with the others following two days apart, leading to significant size differences among the chicks. This difference is a means of regulating the population, as only the stronger chicks can secure enough food during shortages. The chicks fledge at the age of two months, and during their stay in the nest and for four weeks after fledging, the parents provide their food.

The Barn Owl specializes in preying on small mammals, particularly rodents. Analysis of prey remains in pellets shows that about 95% of their diet consists of small mammals found in their habitat, with the rest including reptiles, birds, amphibians, and invertebrates, mostly insects. Among the small mammals, rodents form the main part of their diet, with voles being the most common. The food composition of the Barn Owl shows a high degree of opportunism, adapting to changes in prey species frequency, seasons, habitats, and vegetation cover.

Many studies, including one at Sde Eliyahu, show that the Barn Owl’s daily energy consumption is about 110 grams, achieved by preying on several animals per day. During the nesting season, the predation pressure increases as the parents provide for the chicks. Research at Sde Eliyahu indicates that the parents bring more food to the nest than required, with uneaten rodent carcasses found daily along with the emitted pellets. This increased predation pressure on rodents is significant when considering the Barn Owl as a biological exterminator.

Processed from: Shauli Aviel, Yoav Motro, Dr. Gila Kahila Bar-Gal, Dr. Yossi Leshem; Barn Owl as biological rodent pest controllers, farmer’s background material. 2003.