The Ferruginous Hawk

The Ferruginous Hawk is one of the largest birds in North America. It is 22 to 27 inches long and has a wingspan of close to 5 feet. It is a stocky bird with long, wide wings and a long, broad tail. The back and top surface of the wings are rusty-colored with a lighter rust along the feather edging. The head and face are streaked with white. The throat, breast, and belly, as well as the tail and the underside of the wings are mostly white. The light underside coupled with its dark legs forms the characteristic 'V' shape. They have a short, dark, hooked beak with a long, yellow gape that extends to below the eye. The legs are feathered all the way down to the talons. The female is similar in appearance, but is considerably larger than the male. The immature Ferruginous Hawk is brown instead of rust colored and has streaks on its chest and belly.

The Ferruginous Hawk inhabits the grasslands, deserts, and open-areas of western North America. They prefer the arid and semiarid regions of the country. The Ferruginous Hawk inhabit rolling prairies, foothills, canyons and gullies, but usually avoid high elevations and forest interiors. They are permanent residents in the central part of their range, but the northern birds usually migrate. They spend the winter in the southern part of the United States and Mexico.

During the breeding season, the Ferruginous Hawk prefers grasslands or arid shrub lands. They are highly adaptable and will build their nest in a tree, on a ledge, in rock or dirt outcrops, on platforms, and even on the top of telephone and power poles. Nest sites are often reused from year to year.

The nest is built from available debris such as sticks, branches, paper, rubbish, cornstalks or plastic. Bark from trees and shrubs will be used for lining along with grass and cow dung. The male and female work together to build the nest, but the male does most of the gathering while the female focuses on arranging the nest.

The female usually lays 3 to 4 eggs but the size of the clutch varies depending on the food supply. When food is scarce, fewer eggs are laid. The eggs are incubated for 32 to 33 days. The young fledge at 5 to 6 weeks and reach maturity around 2 years of age.

The Ferruginous Hawk usually hunts small to medium-sized mammals. Mammals such as jackrabbits, pocket gophers and ground squirrels generally comprise 80 to 90 percent of its diet but it will also take birds, reptiles and occasionally insects.

The Ferruginous Hawk searches for prey while flying over open country, or scans the territory for movement while perched in a tree. If its prey's burrow is known, it may wait by the entrance and ambush it the moment it surfaces.

Whether hunting from the air or waiting near a burrow to ambush its prey, the Ferruginous Hawk is a formidable hunter. It seizes its prey with its talons and metes out a series of blows while driving its rear talon into the body to puncture its vital organs. Ever cautious, the Ferruginous Hawk will eat the head of its prey before carrying it to the nest.

The Ferruginous Hawk is graceful in flight with each beat of the wing smooth and fluid. When soaring the wings are held in a strong dihedral but when gliding the wings are held flat.

The number of Ferruginous Hawks dropped drastically in the 1970's and 80's. Some studies show a continued decline while others have documented an increase. The Ferruginous Hawk is on the federal Species of Concern list but is not currently listed as an endangered species.