The ferruginous hawk, or Buteo regalis, is a bird of prey. It is the largest hawk in North America with a wingspan of 48-60 inches (120-150 cm), a length of 20-26 inches (51-66 cm) and a weight of approximately 2.2-4.5 pounds (1,000-2,000 g). In appearance, the ferruginous hawk is rust-colored on its back and shoulders, in contrast to being almost all white on its belly, breast and tail and under its wings. Distinctively, the ferruginous hawk is one of only two hawks with feathers covering its legs all the way to its talons. The sexes have identical markings but differ noticeably in size, with the female being the bigger bird.
As a habitat, this hawk prefers the deserts, grasslands and open plains of North America. It frequents regions that are arid and semiarid in climate. The ferruginous hawk avoids cliff areas, high elevations, narrow canyons and forest interiors. It most often is found on prairies, in foothills with few trees or on rocky outcrops in shallow canyons.
Geographically, these hawks are distributed throughout western North America. Since they migrate only over short distances, their winter and summer habitats are similar. The westernmost range of their territory is from eastern Washington to southern Arizona in the United States. Its easternmost range follows the prairies of the southern Canadian provinces of Alberta and Saskatchewan south to Texas and northern Mexico.
During breeding season, it prefers sage, grasslands or an arid landscape of shrubs, because it likes to nest in open areas. Among birds of prey, the ferruginous hawk is one of the most adaptable as far as where it nests. It will use ledges, trees, the ground or even power poles. Nests are made mostly of ground debris such as sticks or tree bark, but manmade items such as paper or barbed wire also are used. Both sexes build the nest, and they share incubation duties.
On average, three to four eggs are laid. The female ferruginous hawk cares for the nestlings. Males usually take flight at 38 to 40 days, and the initial flight of females comes approximately 10 days later. Young hawks begin to learn to hunt immediately, but remain they dependent upon their parents for several weeks.
Ferruginous hawks are carnivorous and prey mainly upon small mammals, but they also will eat some reptiles and birds. These hawks usually hunt by observing from a perch or while soaring. They also are known to wait on the ground for a prairie dog or gopher to emerge from its hole.