Great (Horned) Owl or the Greatest?

Tim Iverson
Seasonal Naturalist
Cunningham Falls State Park

(1/2013) Part of the mission of the Scales & Tales program from Maryland Park Service is to provide enriching programs that educate people on the tales of each and every animal in their care. People have the opportunity to visit any of the six aviaries in the state, but you can also pay to have the animals come to you! There are various interpretive programs to choose from or you can choose a "Wildlife on Display" format. Recently a Naturalist at Cunningham Falls was telling me a story about a 13 or 14 year old girl he met while doing a display at Hagerstown Community College this past spring. One of the birds on display at this event was the Great Horned Owl, and this youngster sure knew her stuff! Upon seeing the bird she exclaimed "Oh, I know why they’re called Great Horned Owls. Horned: because the feather tufts on their heads look like horns. Owls: because they are owls – duh! And great: because… well they do a lot of stuff really well." And in a nutshell I don’t think I could explain it better in three sentences myself.

Great Horned Owls are the most common owl in the Americas. They are distributed all over the continent from coast to coast, and from the arctic down through Central America. They are also found in many parts of South America, as well. These habitat generalists can be found nearly anywhere potential food can be found – which is anywhere! Rarely do they make their own nests, and instead improvise. They are known to make home sweet home of abandoned nests of other birds. However, more frequently they will roost in tree cavities, stumps, and caves. For this reason they are found in less urban areas.

These birds are the second heaviest owl in North America, second to the Snowy Owl. The Great Horned Owl weighs in at an average of 2 – 4 lbs, or about as much as a phone book. They measure up to about 1.5 – 2 feet and have a wingspan of 3 – 5 feet. That may not seem like much, but they pack a serious punch. It’s said that pound for pound they are some of the fiercest predators around because they can kill prey much larger than itself. Usually, their diet consists of rodents (mice, rats, voles, squirrels, etc.), rabbits and hares, smaller birds and owls, reptiles, amphibians, pets (yes, cats and dogs), and the list goes on! They are known to go after much larger prey too! Small fawns and alligators have been documented prey, but they must be eaten where killed because they’re too large to drag away. However, the most interesting, and one of their favorite meals, is the skunk. Yep, you read right – the skunk. Most birds, with the exception of the vulture, have no sense of smell so this defense does little on behalf of Pepé Le Pew. Between 6 and 12 hours after prey is consumed Great Horned Owls produce what is referred to as an "owl pellet". These pellets, which are about 3 – 4 inches long and about an inch wide, are a pill shaped regurgitation of the leftovers they couldn’t digest. These pellets are made up of fur and bones.

These raptors are quite impressive hunters. Their talons are razor sharp and they are capable or squeezing their feet with up to 200 – 300 pounds per square inch. The Great Horned Owl hunts by perching high up and pouncing on prey. Gifted with incredibly acute vision owls can see well at night. Believe it or not their eyes are almost as large as a human’s, and take up a majority of space in the skull. Proportionally speaking if a human’s eyes were similarly sized we would have eyes the size of soft balls! With eyes that big it leaves little room for much else, including muscles to make them move. Because of this the Great Horned Owl must turn its head to see. The neck has 14 vertebrae, twice as many as a human, which allows them to rotate 270 degrees around. The only thing that rivals their sight is their hearing. The ears are slightly offset from one another, the right being positioned slightly higher on the head. This may seem strange, but provides for exceptionally finely tuned hearing. This allows for both depth perception and elevation perception. By turning their heads so both ears are evenly aligned at a sound the owl can pinpoint the exact location of a noise.

Imagine you’re a hungry Great Horned Owl and chasing down prey on a dark moonless night. You’re going in for the catch when you snag your wing on something, a large wire from a power line! You plummet out of the sky and descend helplessly to the ground. This injury is life shattering, because as a bird a broken wing can end it all. Imagine another scenario, an all too common tale among raptors. You are perched aloft in a tree sitting by a road. You’re patiently waiting for dinner to present itself, and it does! First, you hear some rustling. You scan the ground to find a mouse rummaging around in a paper bag scattered on the edge of a road. You sense the moment is right and swoop down for easy pickings. Then just when you swoop across the asphalt a pair of headlights come careening at you. These stories are all too common among raptors, and the true tales of many of the birds housed at aviaries at parks across the state.

The aviary at Cunningham Falls is home to two Great Horned Owls, one male and the other a female. Both of these raptors, along with all the others housed there, are non-releasable due to permanent injury. The male can no longer fly because of a torn tendon in his wing caused by flying into a power line. The female was struck by a car and as a result had one wing amputated. These owls and the other raptors that call home to the aviary at Cunningham Falls State Park are all available to be adopted, and the proceeds from these adoptions goes directly back into funding programs, health needs, any materials needed, and more! Once the Manor Area reopens fly on by the aviary to check out these masters of the night sky, and the other raptors!