Ferruginous Hawk

The Ferruginous Hawk (Buteo regalis) is a magnificent and powerful raptor of the North American West. Standing out as the largest of the continent's Buteo species, it is often compared to an eagle in size and flight profile. Its name, derived from the Latin ferrugo (rust), perfectly describes the beautiful rufous-orange coloration gracing its back, shoulders, and legs. An open-country specialist, this hawk represents the wild, expansive grasslands, shrubsteppes, and deserts of the Great Plains and Great Basin.

Identifying a Ferruginous Hawk requires looking at its proportions and color patterns, which vary across distinct light and dark morphs.

Key Field Marks

• Size and Structure: Eagle-like proportions, broad wings with slightly pointed tips, a large head, and a massive bill. The bright yellow gape (the fleshy corner of the mouth) is unusually deep, extending all the way beneath the eye.
• Feathered Legs: Along with the Rough-legged Hawk and Golden Eagle, this is one of the few North American raptors with legs feathered to the toes.
• Light Morph (Most Common): Distinctive rufous-brown back and shoulders contrast with a clean, snowy-white breast. When perched or flying overhead, look for the dark rufous-colored leg feathers which form a conspicuous 'V' shape against the white belly.
• Dark Morph (Rare): Deep, warm chocolate-brown to chestnut-colored body. In flight, the underwing shows extremely bright, contrasting white flight feathers.
• Tail: In both morphs, the upper surface of the tail is pale, whitish, or light gray, usually lacking dark terminal bands, though often showing a soft pinkish or rufous wash.
• In-Flight Profile: Glides with wings held in a slight dihedral (a shallow 'V'), similar to a Turkey Vulture, but far more stable.

Similar Species

• Red-tailed Hawk: Smaller with a shorter gape, bare yellowish legs, a dark-spotted belly band (on light morphs), and a distinctly rufous-red tail on adults.
• Rough-legged Hawk: Also has feathered legs, but features a dark belly patch, a prominent black terminal band on a white tail, a much smaller bill/gape, and is usually seen in winter farther north.
• Golden Eagle: Significantly larger with a uniform dark appearance, and lacks the bright white underwings of the dark-morph Ferruginous.

Unlike forest-dwelling raptors, the Ferruginous Hawk is strictly an inhabitant of wide-open spaces.

Habitat Preferences

This species favors native grasslands, sagebrush shrubsteppes, saltbush flats, and desert valleys. It avoids heavily forested areas, narrow canyons, and high-density urban environments. It relies on open areas with low vegetation that allows it to easily spot moving prey.

Geographic Range & Migration

• Breeding Range: Extends from southern Alberta, Saskatchewan, and Manitoba in Canada, south through the Great Plains and Great Basin of the western United States, down to northern Arizona and New Mexico.
• Wintering Range: Many northern populations migrate southwards into the southwestern United States and down into northern Mexico, though some individuals in the Great Basin and Plains remain year-round if food is abundant. They congregate in areas with high mammalian prey concentrations.

The Ferruginous Hawk exhibits fascinating hunting and nesting strategies tailored to its open-country life.

Diet & Hunting Behavior

This hawk is primarily a mammal specialist. Ground squirrels, prairie dogs, pocket gophers, and jackrabbits make up over 80-90% of its diet. They employ several hunting strategies:

• Perching: Scanning the landscape from fence posts, utility poles, or rock outcrops.
• Hover-Hunting: Hovering in place over hillsides like a giant American Kestrel, using the wind to stay aloft while searching the ground.
• Ground Foraging: Walking on the ground to capture insects or waiting patiently next to a prairie dog burrow to ambush emerging mammals.

Nesting

Nests are incredibly bulky structures made of sticks, bones (historically bison bones), and debris. Because trees are scarce in their habitat, Ferruginous Hawks are opportunistic nesters, building either on cliffs, dirt outcrops, trees, utility poles, or directly on the ground. They are famously sensitive to human disturbance during the early stages of nesting and may abandon their territory if approached.

Vocalizations

Generally quiet outside the breeding season, they emit a harsh, raspy, or nasal alarm call when defending their nests, sounding like a piercing kree-ah or kahrr, somewhat throatier and lower-pitched than a Red-tailed Hawk's scream.