The Great Horned Owl (Bubo virginianus) is a highly adaptable species which can be found across a large swath of North and South America, all the way from Northern Alaska to the very tip of South America in Tierra del Fuego.
They are distinguished by their large ear tufts (or great horns), large yellow eyes, and white patch of feathers at the throat. Their huge eyes give them excellent night vision, but because of their size they are not able to rotate within the eye socket. Instead they must rely on movement of the head to direct their gaze, and have thus developed the ability to rotate their heads an astonishing 270 degrees! If human eyes were the same relative size, they would be as large as grapefruits! The most recognizable call of the Great Horned Owl is its deep “Hoo-Hoo”, but adults will also make clacking noises with their beak when aggravated and young owls make a distinct high pitched “shriek.”
The Great Horned Owl is one of the larger owls in North America, on average their wingspan is about 1.4 meters, yet they weigh only 3 pounds! They are so light, because unlike terrestrial mammals, birds have hollow bones. This adaptation is great for flight, but it also means that bird bones are very fragile and are difficult to mend after breaks or injuries. Many of the resident birds in the Outdoor Wildlife Complex are here because of improperly healed wing injuries.
These owls may look adorable, but they are formidable hunters. Often called “the Tiger of the Air” they are able to hunt and consume a variety of species, including snakes, rabbits, other owls, and occasionally even larger prey! In addition to their excellent vision, these owls are able to hear and pinpoint sounds up to 900 feet away. Their dish shaped faces funnel sound towards them, but because their ears are asymmetrical (one is higher than the other), they are able to isolate the location of the noise and adjust their flight path accordingly. Owls are not able to chew their food, and instead swallow their prey whole or in large pieces. This means that they ingest all of the things we usually try not to eat, like bones and fur. Afterward owls regurgitate these indigestible materials in the form of owl pellets.
Although the winter may not seem like the ideal time to have young, the Great Horned Owl profits from the lack of competition for nests and food during these desolate months. You may often find them inhabiting the nests of other birds from the seasons before, just like this owlet pictured in what was once an Osprey nest! The Great Horned Owl uses this time to allow their young to grow, so they will be able to learn to hunt before the next winter. Young are cared for by both parents for up to several months, but may begin climbing and exploring branches after several weeks.
Keep your eyes and ears open for Great Horned Owls and owlets this winter! If you hear them calling, you’ll know exactly HOO it is!
by Kimberly Stever