Great Horned Owls, unlike most species of birds who lay their eggs in the spring, begin their nesting season during the winter months. This mostly nocturnal raptor is a fierce predator. With a nearly 5 foot wingspan it is known to take down prey as large as a Canada Goose, but feeds primarily on small mammals. They usually swallow their prey whole, later regurgitating pellets made up of indigestible teeth, bone and fur. Read about how owl feathers have evolved structures that allow silent flight here.