Kestrel Falcon

by Andrea Johnson

The America kestrel (Falco sparverius), previously known as the sparrow hawk, is one of the most common falcons in Oregon.

Locally, kestrels can be seen perched on poles or wires along the highways and rural roads that line their habitat. Kestrels prefer open spaces including agricultural land, grasslands, deserts, mountain meadows and some urban areas.

Kestrels are distinctive-looking falcons with bright plumage. The male is more colorful than the female and the sexes can be distinguished by their coloring in the juvenile stage as well as in maturity. The male is primarily brownish-red on its back, has a bluish-gray head and wings, a cinnamon colored chest, and black tail feathers. Most of the chest and back are dotted with black spots. The female is similarly marked as the male, but has more brown and less blue-gray.

Kestrels are 9-13 inches long, and have 20-24 inch wingspans. As is characteristic of raptors, the female kestrels are slightly larger than the males. Kestrels are hunters, eating primarily insects, small mammals and birds. Rarely, they will eat small snakes and lizards. Kestrels watch for unsuspecting prey from high on a perch or in midair where they "hover" by flying into the wind at the same speed as the wind.

Kestrels are monogamous and both the female and male help in raising the young. Breeding usually begins in April following courtship displays and nest selection. The nest is usually inside a cavity in a tree - often the abandoned nest of a woodpecker - but nest boxes, hollows in cliffs, and other sites may be used. There are usually four or five eggs laid, which hatch after 29-30 days of incubation. The female incubates the eggs, but once the chicks hatch the male is primarily responsible for bringing food to the nest for the chicks. The young birds are independent after four to five weeks.

References used:

Csuti, Blair et al.: Atlas of Oregon Wildlife. 1997.
Erlich, Paul et al.: The birder's handbook: a field guide to the natural history of North American birds. 1988.
Perrins, Christopher (ed.).: The Illustrated Encyclopedia of Birds. 1990.
Roest, Aryan.: A Contribution to the Natural History of the Sparrow Hawk, Falco sparverius. 1954.