Illinois Natural History Survey - University of Illinois

 

Long-eared Owl

 

Susan Post

 

The arrival of winter is not heralded by any calendar date for me, but by the arrival of Long-eared Owls at a local park. They arrive in December and usually stay until February, providing glimpses into the life of a silent predator.

Owls are efficient predators designed for darkness. They have broad wings so their weight is spread over and supported by a relatively large surface area when they are flying. Their feathers are finely fringed, the edges providing a damping down of the movement of air rushing around the surface. This enables owls to make their way in and out of the shadows in silence. Owl eyes are large and located in a forward position on their faces. This forward position allows a part of the visual field to be scanned by both eyes. They have widely spaced and highly developed ears, which are situated just behind the eyes and covered by head plumage. These aid in homing in on nearly silent and elusive prey.

The Long-eared Owl, Asio otus, is widely distributed in North America, Eurasia, and Northern Africa. At one time Illinois supported a sizable breeding population. Now most sightings of Long-eared Owls in Illinois are during November to mid-March when they are winter residents.

The Long-eared Owl is a medium-sized woodland owl, larger than a Screech Owl but smaller than a Great Horned. Its plumage is brown to buff with heavy mottling and barring. These vertical striations match the striated bark of the coniferous trees in which it roosts. It has wide, staring yellow eyes, heavily feathered legs and feet, an orange face (facial disc), and distinctive long ear tufts. If danger should threaten, the owl presses its plumage to its body and stretches upward, ear tufts erect, assuming a long thin posture and appearing like a broken off stump.

These owls roost (spend the daylight hours) perched near tree trunks in dense foliage, making themselves rather invisible. Long-eared Owls prefer roosts that are adjacent to open grassy, marshy, or desert areas used for hunting. Where available they prefer stands of young conifers for roosting as well as breeding. In the winter roosting birds seek sheltered places that provide cover, easy access, and escape. Prime locations have a southern exposure that will block northerly or westerly winds and catch the warming rays of the sun. Small open areas surrounded by heavy cover are ideal.  Winter roosts of Long-eared Owls may contain up to 50 individuals.

Long-eared Owls usually begin their activity at dusk, gliding noiselessly and low to the ground. They hunt by ranging over fallow fields, clearings, and grasslands and usually hunt from dusk to just before dawn, flying at about three to seven feet above ground with their heads canted to one side listening for prey. If prey is spotted the owl stalls and drops down with its talons spread, pinning the animal to the ground as it absorbs the shock of the bird’s weight. Small prey is usually swallowed immediately. Voles are the most common prey but deer mice, squirrels, rabbits, and birds may be taken.

Once prey is captured, Long-eared Owls, like most other owls, bolt their prey whole. The stomach juices of owls are less acidic so once the soft parts have been dissolved, the indigestible fur, bones, and teeth are regurgitated as tightly packed pellets. Long-eared Owl pellets are oval or cylindrical, grayish, and about two inches long and three-quarters of an inch thick.  They are regurgitated three to four hours after a meal.

While males may begin their territorial calling in the winter, nesting occurs from mid-March through May in North America. Old stick nests of crows, herons, or hawks are often used. These nests are mostly located in wooded sites, often with a screen of shrubbery or branches and are 15 to 30 feet above ground. These old nests are lined with strips of bark, feathers, leaves, and moss before the four to five eggs are laid.  Incubation of the eggs is 25–26 days with hatching occurring over a period of several days. While the nestlings are capable of flight after five weeks, they are not independent of the parents until after two months.

Natural enemies of Long-eared Owls include the Great Horned and Barred owls. Raccoons are major predators of eggs and nestlings.

 

Download PDF



Illinois Natural History Survey

1816 South Oak Street, MC 652
Champaign, IL 61820
217-333-6880
cms@inhs.illinois.edu

Terms of use. Email the Web Administrator with questions or comments.

© 2017 University of Illinois Board of Trustees. All rights reserved.
For permissions information, contact the Illinois Natural History Survey.

Staff Intranet
Login