Distribution and Habitat

Habitat during both summer and winter includes grasslands, deserts, and other open areas with isolated shrubs or trees where less than 50% of the land is under cultivation. During winter, Ferruginous Hawks are often found around colonies of prairie dogs, which make up much of their winter diet.

Natural History

Identification

Often seen while soaring, these hawks are rust-colored on the back and shoulders, mostly white under the wings and on the breast, belly, and tail (which lacks the dark bands of other hawks). The rust-colored legs contrast with the white body and look like a dark "V" when the bird is flying overhead. This is the largest hawk in North America, with a 53" wing-span. It gets its name, Ferruginous (fer-OO-jin-us) from the red coloration, like rusty iron (ferrous).

Did you know?

In the Old West, Ferruginous Hawks used not only sticks but also bison bones to build nests, and used bison wool and manure to line the nests.

Breeding and Nesting

Ferruginous Hawk with Telemetry Device
Ferruginous Hawk Nest

Nesting: begins as early as mid-March in Colorado and Kansas, but in most other prairie states nesting does not start until May. Young leave the nest during late June and July.

Eggs: are usually 3 or 4 (but sometimes as many as 6), 21/2 " long, off-white, sometimes with brown blotches.

Nest: A bulky stick nest 3' across and 2' tall, in an isolated tree or within a small grove of trees. Nests can also be placed on other elevated sites such as large shrubs, rock outcrops, buttes, haystacks, transmission towers, and low cliffs. The same nest can be used year after year, with the birds adding more sticks each year-some nests are 12-15' tall. Nests are located adjacent to open areas such as grasslands or shrublands.

Food Habits

The primary prey of this species is mammals with hares, rabbits, ground squirrels, and prairie dogs comprising the majority of their diet.