It is aggressive and powerful and chiefly nocturnal. The Great Horned Owl is a resident throughout North America south of the tree line. It lives in forests, woodlands, thickets, chaparral, streamsides, open country, deserts, canyons and cliffs. Sometimes the Great Horned Owl will lay its eggs in the old nest of a heron or a hawk, but they also build their own nest in a tree, pothole, cliff or river bluff, and sometimes even on the ground. In North America the Great Horned Owl begins to breed in the cold of winter.
Incubation is around thirty days, with both parents taking turns.
The owls feed on rabbits, squirrels, rats, wild birds including crows, ducks and other owls. Sometimes they will take on an animal as large as a skunk. The frequency of these color phases varies from region to region, but in central Canada and Alaska, the white phase appears to be dominant.