Photo by U.S. Fish & Wildlife Service/Dave Menke                          A Great Horned Owl surveys its woodland domain.

As I sit at my desk on Halloween night to make this blog post, I’ve just come indoors after listening to the resident pair of great horned owls. For much of October, I’ve been treated to dusk serenades by this pair of owls that have taken up residence in the woodlands around my home.

These large owls begin producing their low, deep hoots about a half hour before dusk and continue throughout the night. Activity usually increases again an hour or so before sunrise. The call of this owl has been described as a deep, stuttering series of four to five hoots. It should come as no surprise that “hoot owl” is a common nickname for the very vocal great horned owl.
In addition to great horned owls, several other species of owls reside in the region, including Eastern screech-owl, barred owl, and barn owl. A fifth owl, the tiny Northern saw-whet owl, can be found at some high-elevation locations. A few other owls have made sporadic appearances in the region, including long-eared owl and short-eared owl.

Painting by Louis Agassiz Fuertes depicting a great horned owl with one of its primary prey species, a snowshoe hare.

I’ve heard some experts suggest that the smaller Eastern screech-owl will try to avoid the territory of its much larger relative. That does strike me as a sensible precaution, but I’ve been hearing the wailing, trembling calls of screech owls in addition to the hoots of the great horned owls. Perhaps they’ve struck up an uneasy truce.

The great horned owl is widespread in the Americas and is one of the more frequently encountered owls in the region. A fearsome nocturnal predator, the great horned owl has rightly earned this bird another nickname — “Tiger of the Night.”

Although rabbits are its most common prey, this large owl is not a finicky predator. The great horned owl has been known to capture and consume everything from armadillos and muskrats to geese and young American alligators. They will also prey on various amphibians, fish, crustaceans and even insects. The great horned owl is also known to prey on smaller owls, which includes almost all of the other owls found in the region.

Photo by Bryan Stevens                                                                This Great Horned Owl is a non-releasable bird that is part of a raptor program at Callaway Gardens in Pine Mountain, Georgia.

All owls are extremely beneficial predators, and the great horned owl is no exception. If not for owls and other predators, prey species — whether rodents or insects — would multiply beyond the means of the environment to support them. Anyone facing the problem of mice and rats seeking an easier living inside a human home can appreciate the role played by predatory owls.

The great horned owl, known scientifically as Bubo virginianus, is an exceptional bird for many reasons. The great horned owl is about 25 inches long with an equally impressive wingspan of between three and five feet. The structure of an owl’s feathers are what enables these winged predators to fly silently through the shadows. Its eyes are extremely large, even for an owl, in relation to the size of the owl’s brain as well as overall body size. This owl’s eyes are just slightly smaller than the eyes of a human being and rank proportionately among the largest eyes of all terrestrial vertebrates. Great horned owls, and other owls in the Bubo genus, are know for their formidable talons. Once these talons close on prey, the owl is capable of exerting a pressure of about 300 pounds per square inch.

Early American naturalist and artist John James Audubon painted this part of Great Horned Owls.

In common with many hawks, the female great horned owl is larger than her male counterpart. These owls begin nesting early in the year, usually in February and March. Nest-building activity in January, however, is not unheard of. Great horned owls often take possession of a previous year’s nest built by such birds as red-tailed hawks, bald eagle nests, crows and herons. Some great horned owls will simply claim a cliff ledge for a nesting site.

Early naturalists in North America were duly impressed by the great horned owl. John James Audubon, the early American painter best known for his “Birds of America,” studied this owl around his frontier home in Kentucky. He also wrote about the great horned owl in a journal he kept during a boat trip on the Ohio and Mississippi rivers in 1820-21.

For the average person the term “owl” is representative of what is actually an extremely diverse family of birds. Worldwide, there are about 220 species of owls varying in size and habits.

The genus of Bubo owls consists of some large, powerful species, including Eurasian eagle-owl, one of the largest species of owl in the world, as well as snowy owl, pharaoh eagle-owl, spot-bellied eagle-owl and the lesser horned owl of South America.

Photo by U.S. Fish & Wildlife Service/Susan Rachlin                   A Great Horned Owl locks its fearsome stare onto something at  John Heinz National Wildlife Refuge, Pennsylvania.

Many species of owls have proven capable of thriving even in the face of human alteration of the environment. Both the great horned owl and the Eastern screech-owl are known to hunt in both rural and urban areas. They also can make a home in a suburban park. In fact, the great horned owl has proven extremely adaptable and can be found in such varied habitats as forests, swamps and deserts.

I’ve seen great horned owls in Tennessee, Virginia, South Carolina and Utah in environments ranging from coastal wetlands to arid grasslands and wooded mountain slopes. I can personally confirm how eerily silent these large, powerful winged predators are as they glide through the air. I was once shocked when a large great horned owl materialized as if from thin air as I stood at the edge of an extensive wetlands in Shady Valley, Tennessee. Not a single feather rustled as the owl flew over my head and soon disappeared like a silent shadow into the vast wetland.

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Bryan Stevens lives near Roan Mountain, Tennessee. To learn more about birds and other topics from the natural world, friend Stevens on Facebook at https://www.facebook.com/ahoodedwarbler. He is always posting about local birds, wildlife, flowers, insects and much more. If you have a question, wish to make a comment or share a sighting, email ahoodedwarbler@aol.com.