By Jill Henderson – Show Me Oz –
Last night, as I stood outside admiring the way the stars danced brightly in the clear dark winter sky, I heard the unmistakably deep, resonating call of one of the Ozarks most reclusive giants – the great horned owl.
The slow, richly rhythmic call of the great horned owl – a methodical “hoo-h’HOO, hooo hooo” – seemed to bubble up from the depths of the woods before falling silent. I waited for what seemed like an eternity in the cold air, longing to hear just one more phrase. The forest stood dark and still. Suddenly it came again, this time a little clearer and louder. This was obviously a male owl calling to his mate. I stood wrapped tight in a blanket waiting for the reply. After three tries, the female finally answered her mate with a similar, but softer call that drifted lightly on the breeze.
Great Horned Owls (Bubo virginianus) mate for life. And unlike most birds, they begin their mating ritual in the early fall, usually around November and December when they are most vocal. Once incubation begins in January or February, the pair are mostly silent, with only an occasional communication, such as the one I heard last night.
Great horned owls need deep, mature forest in order to nest and hunt. They also do not build their own nests, but rather reuse the empty summer nests of other raptors. Once a pair chooses a nesting site, there is a good chance they will return to the same area for the rest of their lives so long as they are able to locate an abandoned nest in good condition and the area is not disturbed or destroyed by logging, construction, or fire.
Although I have yet to get a daylight look at either of these magnificent birds of prey, I have had the unique privilege to witness their midnight silhouettes in flight.
Truly giants of the owl kingdom, great horned owls stand upwards of two and a half feet tall and boast a massive wingspan of up to five feet across – enough to rival a small female bald eagle! Such an awesome size would seem to alert potential prey to their presence, but the great horned owl has evolved with a deadly arsenal of stealth and disguise.
Great horned owls are perch and dive hunters, relying on their excellent camouflage to avoid being spotted by potential prey. And while most birds have stiff-bristled flight feathers that generate sound as the wind passes over them in flight, owl feathers have exceptionally soft leading edges that create perfectly silent flight – yet another innovative evolution that increases the stealth of this already capable hunter.
Another tool in the success of owls as predators is exceptional binocular vision, in which each eye captures its own image of the same thing allowing the owls a three-dimensional view of the world. It is interesting to note that owls have eyeballs almost as large humans. But instead of being able to move their eyes in their sockets as we do, owl’s eyes are fixed in their sockets. This is why they have developed the ability to turn their heads up to 270 degrees. If they couldn’t do this, they would only be able to look straight ahead.
While owls do have the ability to see well in the dark, they rely less on their eyes and more on their ears to locate prey. Great horned owls get their name from the two erect tufts of feathers that extend from the tops of their heads. And while these tufts look like ears and are often mistaken for such, the ears of great horned owls are actually located within the conspicuous circle of feathers around each eye. These parabolic-shaped depressions, known as facial discs, amplify the faintest sounds, making owls deadly accurate predators.
An interesting thing about great horned owls is that they are the only bird predator to kill and eat skunks. Obviously not discriminating in their food choices, great horned owls will also prey on other large raptors such as falcons and osprey. They will even prey on other owl species. But as distasteful as one may perceive their diets, owls serve to maintain the proper ecological balance of rodents and other creatures humans think of as pests.
Great horned owls are one of four owl species that live in the Ozarks year round. Other owls found in the Ozarks include the Eastern Screech Owl (Otus asio), the Barred Owl (Strix varia) and the lovely Common Barn Owl (Tyto alba). Every now and again we are graced by the presence of the Northern Saw-whet Owl (Aegolius acadicus), the Snowy Owl (Nyctea scandiaca), the Short-eared Owl (Asio flammeus) and the Long-eared Owl (Asio otus).
Because owls are relatively shy and rarely seen during daylight hours, seeing one during the day is sometimes perceived as a bad omen. Some cultures saw them as harbingers of death. But I suspect that we humans need that part of nature which we cannot always see or understand and the owl is simply a handy symbol of that need. Often when I hear an owl call, I have been thinking on something deeply. So I like to imagine that this mostly silent bird is sympathizing with me, or perhaps telling me how to stay out of danger, rather than being the source of it. To me, owls represent the depth of nature’s ingenuity and remind me to take the time to scrutinize all that is going on around me in my life and to look more deeply into the depths of my soul for the answers that I seek. After all, our stories and myths often describe the owl as wise.
I am an unabashed admirer of birds of prey and the Ozarks are a great place to observe them all year round. We take it for granted that these enigmatic creatures have always been and will always be here, doing their part to balance the ecosystem and to instill in us a larger sense of wonder and amazement. After all, what would a late winter evening be without the haunting and mysterious call of these magnificent creatures? If the great horned owl is to survive in the Ozarks, we must ensure that their habitat is not destroyed due to overzealous logging or short-sighted development. Their very survival depends on us.
Jill Henderson is a naturalist, artist, author, and the editor of Show Me Oz. Her books, including A Journey of Seasons: A Year in the Ozark High Country and can be found in our bookstore.
Copyright Jill Henderson 2011
Image by Brendan Lally, Delta, Canada (Great Horned Owl)