Northern Illinois Raptor Rehab & Education

Discription

Body length: 13.5-20 in.

Weight:  8-21oz

Wingspan:  42-43in. or about 3.5ft

 

Ecology

Most widley distributed of all the owls; however, the barn owl is on the Endgangered Species List in Illinois.The barn owl is a bird of open country such as woodlands, meadows, farm fields, deserts, and urban areas.  Barn owls are cavity dwellers. They choose holes in trees, fissures in cliff faces, the large nests of other birds such as the hamerkop (Scopus umbretta) and, particularly in Europe and North America, old buildings such as farm sheds and church towers.

 

 

 

Hunting Style

This owl prefers to hunt along the edges of woods or in rough grass strips adjoining pasture. It has an effortless wavering flight as it quarters the ground, alert to the sounds made by potential preyThe barn owl hunts by flying slowly, quartering the ground and hovering over spots that may conceal prey. It may also use branches, fence posts or other lookouts to scan its surroundings.

The barn owl's diet is small rodents such as mice, moles, pocket gophers, rats, and shrews.  Prey also consists of birds, bats, reptiles, and insects.  It has been said that during a 10-year period of time, the barn owl may consume upwards of 11,000 rodents which in turn could damage or eat 13 tons of crops.

 

 

 

Behavior

Like most owls, the barn owl is nocturnal, relying on its acute sense of hearing when hunting in complete darkness. It often becomes active shortly before dusk and can sometimes be seen during the day when relocating from one roosting site to another.  Barn owls are not particularly territorial but have a home range inside which they forage.  Outside the breeding season, males and females usually roost separately, each one having about three favoured sites in which to conceal themselves by day, and which are also visited for short periods during the night. 

 

Barn owls will breed anytime of the year, but this depends on food supply.  Females are ready to breed at ten to eleven months of age although males sometimes wait till the following year. Barn owls are usually monogamous, sticking to one partner for life unless one of the pair dies.

 

Before commencing laying, the female spends much time near the nest and is entirely provisioned by the male. Meanwhile, the male roosts nearby and may cache any prey that is surplus to their requirements. When the female has reached peak weight, the male provides a ritual presentation of food and copulation occurs at the nest. The female lays eggs on alternate days and the clutch size averages about five eggs (range two to nine). The eggs are chalky white, somewhat elliptical and about the size of bantam's eggs, and incubation begins as soon as the first egg is laid. While she is sitting on the nest, the male is constantly bringing more provisions and they may pile up beside the female. The incubation period is about thirty days, hatching takes place over a prolonged period and the youngest chick may be several weeks younger than its oldest sibling. In years with plentiful supplies of food, there may be a hatching success rate of about 75%. The male continues to copulate with the female when he brings food which makes the newly hatched chicks vulnerable to injury.  The chicks are at first covered with greyish-white down and develop rapidly. Within a week they can hold their heads up and shuffle around in the nest. The female tears up the food brought by the male and distributes it to the chicks. Initially these make a "chittering" sound but this soon changes into a food-demanding "snore". By two weeks old they are already half their adult weight and look naked as the amount of down is insufficient to cover their growing bodies. By three weeks old, quills are starting to push through the skin and the chicks stand, making snoring noises with wings raised and tail stumps waggling, begging for food items which are now given whole. The male is the main provider of food until all the chicks are at least four weeks old at which time the female begins to leave the nest and starts to roost elsewhere. By the sixth week the chicks are as big as the adults but have slimmed down somewhat by the ninth week when they are fully fledged and start leaving the nest briefly themselves. They are still dependent on the parent birds until about thirteen weeks and receive training from the female in finding, and eventually catching, prey.  Wikepedia

Lifespan in the wild is an average of 4 years (longest recorded is 11), in captivity they can live up to 20 years.

 

Fun Facts

Barn owl's have the best hearing of all th owls.  They have demonstrated this by using their hearing to catch prey in total darkness.  They can even hear a mouse walking across a hard floor from 100ft away.