Barred Owl Life History

Habitat

Barred Owls live year-round in mixed forests of large trees, often near water. They tend to occur in large, unfragmented blocks of mature forest, possibly because old woodlands support a higher diversity of prey and are more likely to have large cavities suitable for nesting. Their preferred habitats range from swamps to streamsides to uplands, and may contain hemlock, maple, oak, hickory, beech, aspen, white spruce, quaking aspen, balsam poplar, Douglas-fir, lodgepole pine, or western larch.Back to top

Food

Barred Owls eat many kinds of small animals, including squirrels, chipmunks, mice, voles, rabbits, birds (up to the size of grouse), amphibians, reptiles, and invertebrates. They hunt by sitting and waiting on an elevated perch, while scanning all around for prey with their sharp eyes and ears. They may perch over water and drop down to catch fish, or even wade in shallow water in pursuit of fish and crayfish. Though they do most of their hunting right after sunset and during the night, sometimes they feed during the day. Barred Owls may temporarily store their prey in a nest, in the crook of a branch, or at the top of a snag. They swallow small prey whole and large prey in pieces, eating the head first and then the body.Back to top

Nesting

Nest Placement

Barred Owls usually nest in a natural cavity, 20–40 feet high in a large tree. They may also use stick platform nests built by other animals (including hawks, crows, ravens, and squirrels), as well as human-made nest boxes. Barred Owls may prospect a nest site as early as a year before using it. No one knows whether the male or the female chooses the site.

Nest Description

Barred Owls do little or nothing to change an existing tree cavity or abandoned platform nest. They may add lichen, fresh green conifer sprigs, or feathers to a stick platform nest, and they may flatten or remove the top of an old squirrel nest. Cavities measure 10–13 inches wide and 14–21 inches deep (sometimes much deeper, with one cavity recorded as nearly 8 feet deep).

Nesting Facts

Behavior

Barred Owls roost on branches and in tree cavities during the day and hunt by night. Territorial all year round, they chase away intruders while hooting loudly. They are even more aggressive during nesting season (particularly the females), sometimes striking intruders with their feet. Pairs probably mate for life, raising one brood each year. Their nests are preyed upon by other large owls and hawks, as well as by weasels and raccoons. When humans interfere with a nest, the parent may flee, perform a noisy distraction display with quivering wings, or even attack. Other birds recognize Barred Owls as predators; small songbirds, crows, and woodpeckers may band together to mob them. Their most dangerous predator is the Great Horned Owl, which eats eggs, young birds, and occasionally adults. Back to top

Conservation

Barred Owls are fairly numerous, and their populations increased 1.1% per year between 1966 and 2019, according to the North American Breeding Bird Survey. Partners in Flight estimates their global breeding population at 3.5 million. The species rates 7 out of 20 on the Continental Concern Score, indicating a species of low conservation concern. Until the twentieth century, Barred Owls were residents of old, undisturbed forests in eastern North America. They were probably restricted from moving into northwestern boreal forests because of frequent forest fires. But fire suppression—along with tree planting in the Great Plains—allowed them to spread northward and westward during the past century. They eventually expanded south along the West Coast as far as California, where they began competing with Spotted Owls. Barred Owls have displaced these slightly smaller and less aggressive owls and have been hybridizing with them, further threatening the already compromised Spotted Owl population. Barred Owls are forest birds and tend to occur in mature forests, because they need large, dead trees for nest sites. These requirements make them sensitive to logging expansion. For this reason, the Barred Owl is often used as an indicator species for managing old forests.

Credits

Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.

Mazur, Kurt M. and Paul C. James. (2000). Barred Owl (Strix varia), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.

Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2017). The North American Breeding Bird Survey, Results and Analysis 1966–2015. Version 2.07.2017. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.

Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.

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