Owls: Strigidae

Most typical owls hunt by sitting on an elevated perch while watching and listening for prey. Exceptions to this hunting style include Northern hawk owls, which hunt like falcons, chasing other birds on the wing. Long-eared and short-eared owls patrol for prey by flying low and slowly over fields. In winter, great gray owls detect voles not by sight, but by the sounds they make under the snow, then plunge-dive. They can break through snow crusts thick enough to support a man.

Many typical owls make classic owl "hoo-hoo" vocalizations, but also use a variety of other vocalizations to communicate. Most typical owls are solitary night hunters. A few, such as long-eared owls, gather in groups in winter to roost. A few are active by day, including burrowing owls.

About 10 percent of all typical owls undergo true seasonal migration. The northern saw-whet owl is one example. Many species in northern regions move south in winters when their rodent prey are scarce.

Most strigids are monogamous (muh-NAH-guh-mus; having only one mate). In a few species (the boreal owl is one example), a male may take two mates simultaneously if food is plentiful. Most members of the group nest in tree cavities, shallow caves, or the abandoned nests of crows or hawks. A few species nest on the ground. Burrowing owls nest in the underground burrows of prairie dogs and other mammals.

The average clutch size is two to four, though eagle owls typically lay a single egg and burrowing owls can have clutches of ten or more when food is plentiful. The female incubates the eggs and broods the chicks while the male feeds the family. The young often leave the nest before they can fly to clamber around in the nest tree. At this stage they are called branchers.