Great horned owls nest in almost every type of situation in which birds nest, a range of variation unequaled by any other North American bird.
From numerous records, it is apparent that the choice of nesting sites of the great horned owls throughout their wide range includes almost every type of situation in which birds nest, a range of variation unequaled by any other North American bird. From extreme heights of almost a hundred feet to badger and coyote dens in the ground, the situations include old nests of other birds and even squirrels, hollow trees and stumps, holes and ledges on cliffs, hay barns, prehistoric ruins, cathedral towers, and even the open ground.
Throughout the timbered regions of eastern North America the birds have been most frequently recorded to occupy old nests of crows, hawks, ospreys, bald eagles, herons, and squirrels. Most of these situations are from twenty to seventy feet from the ground and located near the edge of fairly dense timber.
Hollows in trees or limbs are often reported, especially in the southern states, and in more hilly country ledges on cliffs are not uncommonly described.
In western North America where small caves or niches in cliffs and mountain slopes are available, tree sites are often passed up for these more inaccessible situations.
Old magpie nests are particularly favored in the Northwest.
In treeless regions such as the Prairie Provinces of Canada and the Great Plains of western United States low cliffs, buttes, railroad cuts, and even low bushes appear just as satisfactory as more elevated sites. Ground nests are occasionally reported here and appear to be more common than in other parts of this bird’s range.
In the deserts of the Southwest cactus plants take the place of trees and horned owls often occupy old nests among the thorny branches.