Great Horned Owls

The great-horned owl, Bubo virginianus, is native to much of the Americas, including most of North America and Central America and about half of South America.  It is the second heaviest owl in North America, right behind the snowy owl, Bubo scandiacus, weighing up to five-and-a-half pounds with a wingspan between three and five feet.

Feathers cover the entire body, including their feet, and are varying shades of browns and grays.  Their backs and heads are mottled or barred in several patches.  This coloration, especially when coupled with mostly nocturnal activities, provides excellent camouflage.  Their ‘horns’ are actually feathers sticking upwards on either side of their heads.  These are called plumicorns, but their function is not well understood.  The feather structure of the wing allows owls to fly silently and includes a serrated leading edge to disrupt turbulence and softer feathers behind to help deaden sound.

The owl’s ears are covered by feathers, but are not symmetrical with one being higher on the side of the head than the other.  This arrangement provides the owl with the ability to triangulate sounds and precisely locate prey in the dark or when prey is hidden, such as when an animal is moving about under a layer of snow.  Their flattened face, shaped as a round disc, also helps to direct sound to their ears.  Like all owls, their eyes are fixed in the sockets, but the bird can swivel its head almost 180° to either side allowing it to see in all directions.

Great horned owls hunt from a perch, observing the area below them before diving swiftly and silently from far above.  Their diet consists of small mammals, birds, amphibians, and a variety of snakes.  Their talons are powerful and deadly, with a grip comparable to much larger birds such as golden eagles.  Most prey is killed by being pierced or crushed in the talons.  Owls may hunt and kill for more than their immediate needs and will cache their kills for future meals.

Great horned owls are not migratory.  When an owl is ready to mate, courtship occurs in late fall and pairs mate for life, establishing a territory together in which they will live their entire lives.  Most territorial defense is through hooting at a transgressor, but rare physical confrontations have been observed.  If an owl cannot establish its own territory, it will live in silence among the fringes of other territories.

Males are responsible for picking a nest site, almost always taking over a nest constructed by another species.  Mated pairs breed once every two to three years, laying from one to six eggs.  Egg laying occurs between late February and early April.  The female alone incubates the eggs, never leaving the nest, while the male hunts and brings her food.  After about 33 days, the eggs hatch.  Young owls will start to fly after seven weeks, but take a full month or more to become proficient.

Owls are more often heard than seen.  Although the females are larger than males, females have a smaller voice box and thus a higher pitched hooting call ending with a slight rising note.  Juveniles can make hissing or screeching sounds and are often misidentified as barn owls, Tyto furcata.

You can learn more about these magnificent birds at the Jurica-Suchy Nature Museum.  Make a reservation to come see us by visiting our website at:  https://ben.edu/campus-links/jurica-suchy-nature-museum/  (click on Register to Visit the Museum).