By Maureen Peltier
They are out there in the woods, around your house right now, roosting quietly, getting ready for their nightly forages. There are at least 200 species of owls in the world, including Hedwig, Harry Potter’s mail-delivering Snowy Owl. Here in East Texas we have only four species, and sadly, Hedwig is not one of them, so we have to resort to our normal US postal services.
Really, owls are birds of prey, feeding on small mammals, insects and other birds. They are mostly nocturnal and generally keep to themselves, so we don’t see them often. They don’t nest, but rather shelter inside trees, caves, barns and other birds’ old nests. There are many other unique and truly amazing things to understand about owls, so let’s explore them further.
The four species of owls in our part of the country are the Great Horned Owl, the Eastern Screech Owl, the Barred Owl, and the Barn Owl.
The Great Horned Owl stands 18-25 inches tall and has a wingspan of 36-60 inches. It has the look and stance of what might be a wise professor, staring straight ahead, assessing everything. It has a distinct song of 3-8 bold deep hoots: Whoo! Whoo-whoo-whoo! Whoo! Whoo! Some say that it sounds like, “You awake? Me, too.” It also has what some people think are ears but are really just large ear tufts called “horns” and piercing yellow eyes surrounded by rusty facial disks. It’s a powerful bird that can prey on animals larger than itself, including cats, skunks and possums. It can be active beginning at dusk extending into the night, but it can sometimes be found hunting during the day.
The Eastern Screech Owl is the smallest owl in North America, just 8-10 inches tall, and unfortunately on the decline in numbers because of loss of habitat. Its song is not really a screech but more often described as a mournful whinny, descending in pitch, as “Eee-eeeheee-eee.” It is exclusively nocturnal. Since it’s a little smaller, its eyes are not so piercing, nor as bright yellow like the Great Horned, but it still has that owl look!
The Barred Owl can be found in swamps as well as woods. It is a medium sized owl with a body length of 17-24” but a very large wingspan of 50-60 inches. The Barred Owl has the familiar hoot we recognize, consisting of eight or more drawn out notes that sound like, “Who cooks for you? Who cooks for you all?” (Try imitating its sound when you hear it and the owl will often answer back.) Barred Owls hunt at night and during the day. This owl has more gentle eyes and seems to gaze out sympathetically.
The other owl native to our area is the Barn Owl. It inhabits buildings near areas cleared for agriculture. You can recognize it by its distinctive heart shaped facial disk resembling that of a monkey, long legs and white to cinnamon underparts. The Barn Owl is strictly nocturnal. This species is rapidly declining in some areas due to loss of habitat. It, too, is a beautiful creature.
Consider some amazing facts about these owls. One thing that fascinates us all is how they sit perfectly still and move only their heads in what appears to be a complete circle. How do they do that and why? The answer lies in the fact that they have fourteen vertebrae in their necks, compared to our seven. That feature of their anatomy gives them the ability to rotate their heads horizontally 270 degrees from the front of their body. If we were to do that, we’d quickly cut off the blood supply to our head and suffer a stroke! Their vertebrae have large canals for the blood vessels going to the brain and their carotid arteries unite in a very large junction preventing blood supply from being cut off while their necks are rotating. This gives them the advantage of not having to move their bodies as they silently perch in the trees searching down below for unsuspecting prey.
Owls need to rotate their heads because of the anatomy of their eyes, which are also quite different from ours. Our eyes are spherical, enabling us to move them left, right, up and down, but owl eyes are binaural, like binoculars with enhanced depth perception to help them detect small prey far away. They cannot move their eyes within their heads, so they have to rotate their heads to clarify their vision, like we have to manually focus our binoculars until both sides make a vision come in clearly.
Another amazing feature of owls is their ears. Owl ears are asymmetrical, that is, located at different heights on their head. The sound of a rodent rustling leaves in the pitch black of night does not reach both of an owl’s ears at the same time. When a sound reaches his ears at different times, the owl moves his head until the sound arrives in both ears at the same time. He also adjusts the feathers around his eyes to focus sounds from varying distances onto his ears. Thus, this remarkable bird has the ability to pinpoint the exact location of the rodent. Pretty amazing - considering that sound travels at 1,125 feet per second!
Most owls share an innate ability to fly almost silently and much slower than other birds of prey. This ability gives them a great advantage over prey that are listening for the slightest sounds at night. The owl’s unique hearing system and the structure of its feathers gives them that advantage. Their feathers, widely studied by biologists, are generally larger than average birds and are structured in such a way that the flapping of their wings is an almost silent mechanism. The surface of their feathers is covered with a velvety structure that absorbs the sound of the wing moving, making the sound of its flight fall below the typical hearing spectrum of the owl’s usual prey. Because the owl’s hearing is so acute, he can also monitor his own sound as he approaches his prey. These birds are true stealth flyers.
Owls have appeared in legends for thousands of years in all types of cultures. They have been labelled both symbols of wisdom and omens of death. Whether we call them magical or mysterious, we always admire their amazing features and incredible abilities. Owls are pretty special.
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