When we think of top predators our thoughts are drawn to sharks, wolves, Mountain Lions, and some bears. There are a number of birds of the sky that can claim to be a top predator. But none of them are as fierce and aggressive as the Great Horned Owl. In Eastern Nebraska where predators such as Grizzlies and wolves were exterminated by early settlers, the Great Horned Owl has become the master.
Great Horned Owls are the second largest owl in North America, slightly smaller than the Snowy Owl. They stand 18” to 25” high with a wingspan that can reach 60”. The weight varies from 3 lbs. to 4.5 lbs, the female being 10 to 20 percent larger than the male. Their name came from the two horned like feather tufts on top the head which are neither horns nor ears. They are just that, feather tufts, used as part of their camouflage when roosting during the day making them appear as a broken branch or limb of a tree. The color patterns of owls help them blend in with their surroundings as well. Great Horned Owls can vary between a reddish color to a grey color with black and white. The underside is a light grey with dark barring up to the neck which has a whitish band. As with most owls the eyes are yellow.
Their range is expansive. They are found from the North American Tundra south beyond the Equator into the Rainforests, making them the most common owl in the Americas. The habitats used by Great Horns are just as diverse. Their preference is open woodlands and woody areas next to open fields. But they can also be found in dense Boreal forests to barren deserts. Treed urban and suburban yards also provide suitable nesting habitats and, where there is human activity, they are sure to find a good number of prey mammals such as rabbits, possums, and raccoons. Even an occasional free-roaming cat has been known to fall prey to the Great Horned Owl. A favorite food of this owl is skunk, or maybe it appears that way since the white stripe on a skunk’s back may make them more visible. Of course it also helps to have a very poor sense of smell which is common among the majority of birds that use sight to find their food.
But the eye-sight of an owl is only about four times better than that of humans. Owls have very large eyes. In fact they are so large there is no room for eye muscles allowing them to move their eyes as we can. But that limitation is offset by an adaptation of 14 vertebrate in the neck which permits them to turn their head a little more than 180 degrees in either direction. This almost makes it appear they can turn their head completely around which is not the case. The vision is further enhanced by the fact they have no “cones”, only “rods” in their eyes so they only see in black & white which is more efficient. Other birds do see in color.
The sensory factor used most by owls when hunting is their acute hearing, after all, when it is dark out eyes are of very little use when stalking and catching prey. The ears are located just behind the eyes with one slightly higher than the other. The openings in the ears are slightly pointed in different directions as well. This allows the owl to turn and tilt its head until equal sound reaches both ears. This capacity to triangulate the sound of prey moving in the dark gives owls the ability to accurately pinpoint their prey’s location. The short feathers around the eyes of an owl referred to as “eye-disks” help to collect the sound and move it toward the ears. These eye disks may even act as an amplifier. But one thing is for sure. Owls rarely miss catching their dinner.
The most remarkable adaptation inherent of owls is their ability to fly silently. This is due to the comb like fringe on the leading edge of an owl’s primary flight feathers and the fluted outside edges. This design reduces the turbulence of air flowing over the wings effectively muffling the sound allowing for silent flight. Even the upper part of the beak as well as the legs and feet has feathers to prevent turbulence. The ability of silent flight keeps their hearing unobstructed from noisy wind turbulence while preventing their prey from hearing the approaching danger.
In Mid-Autumn Great Horned Owls will become quite vocal as pairs will call out to each other from about dusk to midnight, then again just before dawn with the familiar “hoo-hoo hoo-hoo”. The male owl produces a deeper tone than that of the female. Nesting begins in January and February. Great Horned Owls do not build their own nests but take over the nests of other large birds such as hawks and crows.
Cool Great Horned Owl Facts
Great Horned Owls have 500 lbs per square inch of crushing power in their talons. A human has 60lbs per square inch in their hand.
A Great Horned Owl is powerful enough to take prey 2 to 3 times heavier than itself.
Rodents and small rabbits can be swallowed whole while larger prey are carried off and ripped apart at feeding perches or at the nest.
Owls cannot digest fur, bone, and feathers. These materials are regurgitated as a casting called an “owl pellet” twice daily.
The life expectancy in the wild is 13-15 years, although in captivity they can live beyond 30 years.
If we had eyes proportional to those of the Great Horned Owl, they would be the size of grapefruits and weigh 2-3 pounds each!
In Western folklore, owls are commonly associated with studious scholars and wise elders. This may be because of their human like binocular vision and ability to see in the dark.