Great Horned Owls

We have a number of owl species in our part of the world, but the most spectacular is certainly the Great Horned Owl (Bubo virginianis). This bird has a body length of 22", a wingspread of 44" - almost 4 feet - and weights about 3.1 pounds. There are a number of different geographical plumages - our birds are typical Eastern, with rich reddish plumage on the face and body. For comparison, this owl has a longer body and slightly shorter wingspan than, and outweighs, a Red-tailed Hawk. The "horns" or "ears" (they aren't ears, just tufts of feathers) are very distinctive. It's a very big bird, and if you've ever seen one, you know what I mean. Perching, the bird is majestic, and when it's flying, it's truly magnificent, especially as its flight is utterly silent, almost ghostlike. Even the juveniles are large - I had the great good fortune on a bird walk a couple of years ago to closely observe two unfledged juveniles clinging to the trunk of a large tree.

Owls also have, due to their relatively flat faces and front-facing eyes, a very intense stare, and their habit of following your motion with their heads is a bit alarming. They are very successful predators, largely hunting at night and taking a number of prey species, including crows (picked off as they roost), porcupines, rabbits, rodents, skunks, other owls, hawks, pheasants, quail and other birds up to and including Great Blue Herons. They are supposedly the most common predator of domestic house cats (another reason to keep your cats inside). If you're very lucky, you may come upon a set of animal tracks in the snow that ends in wide wing prints where an owl captured its prey.

They have one brood per year, and are nesting now. Sometimes eggs or young are lost to the cold. They nest in tall trees, and have large messy nests. The two or three young hatch after 26-35 days of incubation, and are semialtricial 2 (which means that they hatch covered with down, with their eyes closed, cannot leave the nest and are fed by the parents), and fledge (fly) after another 35 days, although the parents (both parents incubate eggs and tend the young) continue to feed them for several more months. They cache some of their prey, and can defrost frozen prey by "incubating" it.

All owls fly silently because the forward edge of the first primary feather on each wing is serrated rather than smooth, which disrupts the flow of air and reduces the noise made by air passing over a smooth surface. Their hearing is acute, and much hunting success is due to hearing. They have specialized hearing and brain adaptations that allow them to precisely locate a sound in space.

Here is some more information, as well as some nice photos.

References: The Sibley Guide to Birds, David Allen Sibley; The Birder's Handbook, Paul R. Ehrlich, David S. Dobkin and Darryl Wheye; and Great Lakes Nature: An Outdoor Year, Mary Blocksma.