Great Horned Owl in flight.
Photo by Dana Brown
 
Fall 1998/
Winter 1999

Director's Page


Owls



Brown Gap Timber Sale



Pinus Strobus




Chip Mills Proliferate




Update Oconee
Nuclear Station



Letter to the Editor



Book Review: The
Appalachian Forest




Watershed News

 


 

At dusk a couple months ago, I set a cardboard carry-kennel on the deep green lawn of a small park. Live oaks and a tidal creek made the place magical; yet, the mosquitoes made me want to go home. The Great Horned Owl inside the box was home. She (or he?-there is no way to tell, just by looking) had been found that morning, snared in the soccer net at a nearby playground. An examination at our clinic showed no injuries, so we wanted to get the owl home as soon as possible.

So there I was. The owl was supposed to fly up, out, and away. I opened the box and took a seat at a respectful distance. Nothing happened. The Blue jays arrived, raucous and bombing. Still nothing. I approached and tipped the owl onto the grass. Even as I hoped she would come to herself and fly, I knew she was dying.

A few weeks earlier I had taken "Cotton," a Great Horned Owl, to visit an elementary school science class. Cotton's injuries-from colliding with a car-had healed, but not well enough to afford her her freedom. Cotton's perch is one-footed, and to the spectator's eye, there are differences between her good and bad sides. Still, she's magnificent to see.

After our visit, the students found a Great Horned Owl in their school's soccer net. Similar to the other owl trapped in the play ground soccer net, the post-rescue exam showed no discernible injuries. We kept him overnight, and the bird was found dead during morning rounds. We told the children that the owl had died of stress, and I am sure that he did. Surely, a night of frantic effort took a great toll. Would these owls have fared better had they been freed from the nets to fly, and spared the added burden of travel, touch, and confinement? We don't know.

We do know that once owls have hatched successfully and survived the precarious first year, contact with the human world poses the greatest threat to their survival. The owl hatchling is a fine meal for a raccoon or another bird of prey, and starvation looms until the young bird becomes a seasoned hunter. But adult Great Horned Owls, for example, have no natural predators. Ninety-six percent of their deaths are related to humans. They are hit by cars; shot; collide with power lines; entangled in fishing line; or, perhaps caught in soccer nets.

Owls, like other birds of prey, have been actively persecuted by humans. For example, a farmer whose chickens were disappearing surmised that the owl residing in the barn was eating them. So, still on his perch, the bird was an easy target. It is a relatively recent development that enough has been learned about owls to understand their economic value.

Examining owl pellets has been one way to gain insight into the habits of these birds, whose nocturnal habits have made learning from observation difficult. As many school children know, owls eject the parts of a meal they are unable to digest. An owl that has eaten a mouse will caste the bones in a roughly spherical or cylindrical packet that is covered in fur. If he has dined on a bird, feathers will provide the wrapping. Observers now calculate that a Barn Owl consumes about four mice a day, or roughly 1,500 in a year. During a ten-year life span, one owl consumes about 15,000 mice. The advantages are obvious.

Yet, daily proximity with "Cobo," our resident Barn Owl, has given me greater appreciation for how these birds could become the subject of superstition and fear, and be seen as portents of illness or death. Cobo's black eyes are luminous against stark white feathers. On his head, and framing his heart-shaped facial disks, is a heavy dusting of charcoal grey set in delicate cinnamon. Disturbed, Cobo's stooped sway is reminiscent of dementia in humans. Angered, his scream sounds like a horror movie heroine scared out of her wits. The noise has set my neck hairs on end on a brilliant afternoon. I can't imagine its impact in a darkness not penetrated by electricity.

Though the acute hearing of Barn Owls, who can hunt successfully in complete darkness, has been the most studied, we know hearing is of primary importance in all owls. The concave ruff of feathers surrounding each eye hides the owl's ear openings. These feathers also channel sounds to the inner ears.

To use their hearing, owls must approach prey quietly. I continue to be awed each time I enter an owl flight pen and watch them leave the nearer perch to swoop to the next-soundlessly. How can such big birds make so little sound?


Close-up of an owl's primary flight feather, which has a serrated edge to eliminate noise.
photo by Dana Brown

The first primary feather, or flight feather, on each wing has a serrated edge. This eliminates the noise that would be created by air flowing over a smooth surface. Compare the velvety feel of an owl's wing to the more satiny feel of a hawk's, or notice how the feathers on a Great Horned Owl's legs extend to its talons. Owls are designed to muffle sound.

During presentations I sometimes put "Sienna," a reddish-brown Screech Owl, on a table perch. She's eight inches long and weighs about one-quarter pound. Sienna is a crowd pleaser. She rouses, castes a pellet, and turns her head "all the way around." In fact, neither Sienna nor any other owl's head makes a 360 degree turn. Instead, she can turn 180 degrees from north to south through east; then, come back to north and turn another 180 degrees through west-so the head seems to go full circle. Owls, who appear to have no neck at all, can do this because they have the flexibility afforded by fourteen vertebrae, which is double our seven.

Owls' huge eyes take up more room in their heads than their brains do, and enable them to see in the dimmest light. But owls cannot move their eyes from side to side; in order to look around, they must turn. Turning just the head, rather than the body, is an effective way to escape notice-something that is important to an owl, whether she's hunting or resting.

When I returned the soccer net owl to her park, she was quickly mobbed by jays. Songbirds mob predators. A good way to avoid this annoyance, or a more dangerous threat, is to avoid detection. Sienna, safe on her table perch, shows perfect "I'm not here behavior" when I bring a Red-tailed Hawk to a presentation. She becomes still. She lifts her ear tufts, so that her head loses its typical rounded silouhette. She stretches out, so she could easily be confused with a tree branch, if one were around. And she squints her eyes, to hide the noticeable yellow of her irises.

Like all raptors, owls occur in low densities. That, and the fact that they are nocturnal, makes typical bird survey methods inadequate for judging their numbers. However, the conservation status for owls in our region seems to present an encouraging picture. Populations of Great Horned, Eastern Screech, and Barred Owls seem stable. Barn Owls apparently have suffered from the disappearance of farming land; their numbers seem to be declining. Yet they do respond well to nest box programs.

Several years ago on a late afternoon run in my Atlanta neighborhood, I crested a hill and stepped into the easy descent. With a lull in traffic, the silence was exhilarating. Suddenly, at eye level only an arm's length ahead, a large feathered something passed just slow enough to see. A sharp squeal from the bushes, then a slight rustle, and all was quiet again. I stopped and turned. An owl disappeared into the trees. That glimpse of the wild-two blocks from home-put me in my place in the most satisfying and sustaining way. I hope a similar chance encounter will be a possibility for my son, and his children as well.

Back to the Top