Owl Basics

and regurgitating a pellet that is conveniently packaged as a tightly compacted ball of fur, bones, and other material not needed for nutrition.

Their voracious appetite is matched only by eager students wanting to learn about their diet! Another important owl we study, mainly because of the bird’s proximity to the Barn Owl in North and South America, is the Great Horned Owl. Great Horned Owls do not lend themselves as well to our investigations due to differences in how they ingest and digest their food. That being noted, as we work with students across the world, we find a growing interest in the more challenging study of the Great Horned Owl.

If you asked someone what sound an owl makes, most people would say, “Hoo!,” and that’s not necessarily incorrect. But the vocalizations various owls make distinguish them as uniquely as their appearances do. For example, a Barn Owl does not produce a “hoo,” but rather the “screech” that has been the source of many mythical stories told on dark, spooky nights. Screech Owls, on the other hand, rarely screech but rather have a staccato-like succession of hoots. The Great Horned Owl is known distinctly for its “hoo!” and is one of the most commonly heard owls in the wild.

While the Barn Owl is present on nearly all continents, the Great Horned Owl is the most common owl of the Americas. It has feather tufts that can make it somewhat cat-like in appearance. These horns, referred to as “tufts,” easily distinguish it. Great Horned Owls are highly adaptable birds. Their habitats range from suburban areas, to forests, farmlands, and to places

where there is an abundance of prey. Northern subspecies can migrate in winter months but prefer moderate climates where they can live for as many as 5 to 15 years. Barn Owls are cavity dwellers by choice, selecting tree holes, stumps, caves and abandoned structures. Sometimes they take the unoccupied nest of a Barn Owl or other large bird. There have been instances where our staff has seen a Barn Owl living in one end of a large structure and a Horned Owl at the other end. However, this is a rare occurrence because Barn Owls are frequently killed and preyed upon by Horned Owls. For the most part, Great Horned Owls are monogamous, meaning they choose one mate for life. Both parents will incubate their eggs, which can range from one to five eggs (2-3 eggs on average). A group of eggs laid during the same period is known as a “clutch.” Great Horned Owls are fiercely protective parents and known to attack humans who they perceive to be a threat.

Great Horned Owls share the digestive system common to all owls. Similarly, Horned Owls will consume their prey whole when it is a smaller animal. This is followed by the regurgitation of a pellet that includes the fur, bones, and other parts of their prey not required as nutrition. They are known to prey on a huge variety of creatures, including raccoons, rabbits, squirrels, domestic birds, falcons and other owls. Great Horned Owls regularly eat skunks, and are The Great Horned Owl one of the few animals with such an appeis the only animal that tite. They sometimes hunt for smaller game regularly feasts on by standing or walking along the ground. skunks! These owls have even been known to prey upon wandering cats and dogs. Because Great Horned Owls have a more diverse diet that includes small mammals and larger rodents, they often need to break up the bones of an animal in order to digest it. For this reason, it can be more difficult for the inexperienced eye to identify prey in a

Great Horned Owl pellet. Like other birds of prey, Great Horned Owls