Great Horned Owl Courtship Begins

One of  the best things about December is hearing the first calls of the Great Horned Owls as they begin their courtship.  The hooting of the owls becomes noticeable mid-December in Michigan. On a clear nights, even in the suburbs where I live, you'll hear the birds calling back and forth usually from midnight until dawn. Their distinctive territorial call, "hoo-hoo hoooo hoo-hoo," can be heard from miles away.

The courtship calls begin in December but the actual mating is late January or early February. The males hoot vigorously for over a month, while the answering calls of the females are heard for only a week or two, toward the end of the courtship period.

In the beginning males are excited and hooting seems to be an expression of physical vitality. Then males start competitive hooting from favorite perches to defend their territories. Finally the owls hoot to attract the attention of females.  

Great horned owls are monogamous, forming a mating pair to raise the young. They achieve sexual maturity at 1 to 3 years of age. Like all owls, Great Horned Owls do not build their own nest. They often take over a nest used by some other large bird, sometimes adding feathers to line the nest but usually not much more. Old crow, raven, Red-tailed Hawk or large squirrel nests are often favored in North America. They also use cavities in trees, deserted buildings, and artificial platforms. Males select nesting sites and bring the females attention to them by flying to them and then stomping on them.

After a mate is chosen they bow to each other, with drooped wings, rub noses and preen each other. If all goes according to plan the female will lay 2 to 4 eggs and incubate them for 26-36 days. Six weeks after hatching, the owlets become "branchers" when they start to walk in the trees around the nest.

They cannot fly well until 9 to 10 weeks old. Then the parents show them around and teach them how to survive. In autumn the juveniles disperse widely, while the adults return to the area near their breeding grounds. The pair will then each maintain solitary existences until the next nesting season.

The average life expectancy of great horned owls is 13 years. They do not migrate but stay in the same general area.