Many a dark winter night, I hear the low, soft, calls of two Great Horned Owls that come to my neighborhood. One calls with a deeper voice than the other. This is the male. Even though he is smaller than his mate, he has a larger voice box, so his tone is decidedly lower in pitch. The call of the great horned owl is familiar to most. It is what you hear in the nighttime woods on any television show or movie. The call of the “Hoot Owl.”
This pair of owls is undoubtedly hunting for the numerous rabbits that frequent backyards. It isn’t a particularly special neighborhood. It is just your run of the mill, Littletown U.S.A., commonplace among the prairies of the Midwest, but its older trees and wooded creeks make it possible for our owl pair to make a living.
As February rolls around, my owl pair have things other than rabbits on their minds. It is the time of year that the human residents here celebrate Valentine’s Day. In the owl world, they have already set up housekeeping, and are likely sitting on eggs while the last snow of the year falls from the cold, night sky.
Almost all owls are early nesters. The Great Horned Owl commonly claims someone else’s nest. Perhaps it was a Red-tailed Hawk, a crow, or even an old squirrel nest. If your habit is to live in someone else’s home, it makes sense to claim residence before the owner comes home. In this case the early bird gets the nest. Owls are fierce enough predators that very few other creatures will take them to task. They are better off starting over from scratch than having to deal with sharp talons and beak. If a nest isn’t available to take over, Great Horned Owls will choose a hollow tree-snag. They have also been known to take up residence in old, abandoned buildings or grain silos.
Once a nest has been established, the female will start laying eggs and incubating. She will lay from one to four almost round eggs. She will start incubating as soon as the first egg is laid, then lay another egg every other day until she has a comfortable clutch to sit upon. The first egg has a couple of days head start over the next one, so it is possible for the first chick to hatch up to a week before the last one will hatch. This is common practice for birds of prey. Songbirds, like the American Robin will delay incubation until all eggs are laid, and the chicks will all be the same age when hatching.
After around 30-37 days of incubation, the chicks start to hatch. It’s a cruel world for the last chick that hatches. If food is scarce, they will not likely survive. Their older siblings will out-compete them for the food. The female will continue with a majority of the nest duties, and the male will have to wander far and wide to collect enough food for the growing family. Great Horned Owls have a varied diet. They will hunt both mammals and birds and even supplement their diet with reptiles, insects, and carrion. They can dispatch animals with a deadly grip of sharp talons that are designed to sever the spine and damage the internal organs of whatever is unlucky enough to get in their grasp.
After 42 days, the nestlings that have survived are ready to strike out on their own and discover the wide world that is before them. They do this with some real adaptive advantages over other birds. Large eyes allow for excellent vision in the dark. While other birds of prey require sunlight to spot their food. Owls can go after things that travel in the dark. They also have excellent hearing and can actually discern the sound of a mouse scurrying under the cover of snow. If they are successful in making it past the nestling phase and survive to adulthood, they will carry on the tradition for many years. Owls are fairly long-lived for birds in the wild, and it is not uncommon for them to live 20 years.
As February rolls around, the Great Horned Owls in my neighborhood become much less vocal. They have said everything they need to. They have found a mate. They are nesting. The work that will occupy them for the next couple of months is a task that needs action, not words. Such is the wisdom of the owl.