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in Northern California Barn Owls are found all over the worldon every continent except Antarctica. There are 16 known species. In some parts of its range the barn owl is gravely endangered, including Britain and parts of the Midwestern and Eastern United States. The Barn Owl requires a cavity, ledge, or old building in order to raise a family. They will also use artificial nest boxes, as will Screech Owls. Owls do not build nests! Other owls, species that are not cavity nesters - such as the Great Horned Owl, will take over the vacant nests of other large birds, such as hawks and ravens. Owls mostly swallow their prey whole, and approximately 12 hours later they regurgitate a pellet consisting of the bones and fur of their last meal. These pellets, when deposited in the Barn Owls nesting area, create a soft, warm carpet upon which to lay the eggs. They also provide researchers with a clear picture of what the owls are eating. From the study of Barn Owls, and their pellets, it is known that these owls are amazing consumers of rodents and thus extremely beneficial to the environment. In locations where owls have roosted for years excellent studies can, and have, been made of their lives and their diet. Although rodents, such as rats, voles and gophers, are the favored food, the barn owl is opportunistic and will also eat songbirds and other creatures. A family of Barn Owls can consume about 1300 rats per year and 3000 rodents in a breeding season alone! It is for this reason the U.S. Fish and Wildlife Service stated that the barn owl is the most economically beneficial species to humans. The Barn Owl's body is a golden brown on the back. The breast can be a variety of shades from white to golden brown and is usually speckled. Male barn owls are thought to be much whiter on the breast, with fewer spots, than females. Females, as in most birds of prey, can be larger than males. Barn Owls have a long bill and small, dark eyes. The bill doesn't appear very large because it is hidden under feathers, but the mouth can actually open very wide, not unlike a snake's mouth, allowing it to consume large prey items whole.
Barn Owls are known for their tolerance of humans as they often choose to nest in quite close proximity. Sadly though, it is humans who cause a great deal of the barn owl's mortality. The owls natural enemies include the great horned owl (pdf link), which will hunt other owls. There may also be predation of young and eggs by large snakes, raccoons, and squirrels. Most Barn Owls live very short livesonly 2-3 years. As is the case with all wildlife, over 50% will not survive their first year of life. This will be due to starvation, predation by Great Horned Owls (aka the Tiger with Wings), and damage caused by humans such as car strikes, shooting, secondary poisoning, and destruction of nests and habitat. Perhaps because of their high mortality rate, Barn Owls tend to have large families.
Breeding season generally starts in January, February, or March, depending on weather conditions, with the male looking for a suitable nest site. Once he has found a site and moved in, he tries to attract a mate. Courtship behavior begins 6-8 weeks before laying the first eggs. The time of year varies depending on weather and availability of prey. Activity is centered in and around the nest site. Some existing pairs may have roosted together at the nest site over the winter, but most roost apartmales, in particular, roost away from the nest. Males start spending more and more time at the chosen nest site at the beginning of the breeding season enticing their partners into the box. Once the female has accepted a mate, and is ensconced inside the box, she becomes more and more "broody" and she stays in the box for extended periods of time. Before mating, the male presents her with food. Once egg laying and incubation begins, the male continues to mate with the female and bring her food.
View & Hear baby barn owls (30 sec./.wmv file) For owls that are using barn owl boxes, the first signs of an occupied box might be frequent calls around the box at night, scratch marks around the box entrance, or a white ring of feather powder around the box entrance. Another sign might be "white wash" in the vicinity - this is splashes of what looks like white paint, but is actually the fecal matter of the owl. The drainage holes in the bottom of the box may appear blocked if in use because the pellets form a soft substrate in the bottom of the box. It is very important NOT to disturb the box at this time as the females may abandon the nest even if already incubating eggs. If your box is on a pole, avoid touching the pole as any vibration could cause the female to take flight.
This photo of a Barn Owl leaving its box was taken by our friend Phil Johnson. This could be a male Barn Owl because the breast is very white. Hunting is the #1 activity of the Barn Owl and is also when it is most vulnerable. Many Barn Owls are hit by cars while hunting because one of their hunting techniques is to fly low, around 10', over the ground listening with their amazing hearing for the sounds of rodents. If a road happens to cross the fields where the owl hunts, the owl can easily be struck and killed. If you believe you have a pair of owls nesting in your box, please call HOP at 415-454-4587. We will be banding babies again this Summer for our research. Like all birds of prey, Barn Owls are protected by Federal & State laws, and once they have begun nesting in a box, it is illegal to disturb them. Barn Owls have many vocalizations, some quite frightening and eerie. Listen to a Barn Owl (tyto alba). Often times people will think that Screech Owls are living nearby because they hear screeching sounds during the night. In fact, Western Screech Owls don't really screech at all! Listen to a Western Screech Owl (Otus kennicottii). They have soft, descending hoot. The hooting sound that people identify with owls is the Great Horned Owl. Listen to a Great Horned Owl (Bubo virginianus). Barn Owls are the ones doing the screeching. They also hiss, scream in a bloodcurdling way, click and clack their beaks, and make many other strange and wondrous sounds. Baby owls will spend the entire night calling for food with a sound that is hard to describe. Some have compared it to the sound of steam going through pipes, or the sound of an Espresso machine steaming milk, or simply a hissing sound. VOCALIZATIONS: Fifteen vocal and two nonvocal sounds were described by Bunn et al. (1982). B. Colvin (pers. comm.) described the five most frequently heard vocalizations: 1) the "contact call" is a drawn-out screech frequently given in flight when approaching a nest site from a distance; 2) the "alarm call" is an intense screech made in response to human or other disturbance which is typically given at a nest site and only after chicks have hatched; 3) "squeaking/ticking calls" are rapid, high-pitched notes which are associated with pair bond maintenance or distress situations; these calls are commonly produced during courtship, incubation, and first evening flights after chicks have hatched; 4) "snoring" is a greatly varying hiss which is repeated persistently by juveniles in and out of the nest; this call is used for food begging and may be heard at nest sites from sunset to sunrise; and 5) the "defensive hiss" is a very loud and prolonged hiss typically produced by nestlings when disturbed. (Source: The Nature Conservancy, Species Management Abstract. Contributing Author(s): Rosenburg, C.; revisions by G. Hammerson, M. Koenen, and D.W. Mehlman). Barn Owls resemble giant white moths floating buoyantly through the night sky, and seem to disappear at times before your very eyes. With their screams, silent flight, and white appearance it is not surprising that through the ages Barn Owls have been associated with the supernatural. In some Latin American countries they are thought to associate with witches and are sometimes persecuted. In reality, Barn Owls are harmless (unless you are a rodent), beneficial beings who grace our world with their beauty and eternal mystery. Back and forth she floats neither of heaven or earth, she lives in the
inbetween, Oh, the mystery and the beauty of you the silent hunter of the velvet
deep, Shrieking through the night sky the ethereal hunter awakes... - In Memory of Teco, by Alex Godbe
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