With its long, earlike tufts, yellow eyes and deep hooting voice, the great horned owl is well-known in both North and South America — and a common resident in Minnesota’s forests.
Close to 240 species of birds nest in Minnesota. The earliest is the great horned owl, one of the state’s dozen owl species. We have been hearing pairs duet hooting since November as they continue pair bonding and declaring nesting territories. The female usually hoots first, and the male replies in a lower-pitch deep hoot.
The great horned owl is nearly 2 feet in length, with a wingspan of just less than 5 feet. It weighs a little more than 3 pounds. The female is larger than the male but otherwise they resemble one another with a conspicuous white collar and dark-streaked breast.
All birds require an enormous amount of food; the great horned is no different. They have an extremely high metabolism and can process the equivalent of their own body weight in food each day. As predators, there are fewer owls than the food they eat, which is necessary or they would eat themselves out of business. Great horned owls prey on everything from mice, skunks, raccoons and rabbits to squirrels, birds and even other owls. Also, they eat snakes, lizards, frogs and insects. Although they are usually nocturnal hunters, they will hunt in daylight, especially in winter.
Great horned owls usually use old nests of other large birds such hawks, eagles, crows or herons. A broken-off tree stump, usually 20 to 60 feet off the ground, works, too. No nest is prepared by the owl itself. The only contribution the owl makes is a few feathers from its body.
The usual clutch size is two eggs. Following a snow or sleet storm, it is not uncommon to see an owl incubating under a cover of snow or ice. I have seen that happen. Both parents take part in providing food for their young. Young great horned owls might leave the nest and climb on nearby branches at five weeks; they fly at about 10 weeks and are tended and fed by parents for up to several months. This long period of care is the reason for being early nesters. It’s much easier for their parents to provide for their needs before the summer foliage becomes too dense.
Jim Gilbert’s observations have been part of the Minnesota Weatherguide Environment Calendars since 1977, and he is the author of five books on nature in Minnesota. He taught and worked as a naturalist for 50 years.