About Buteo Regalis, the Ferruginous Hawk About Buteo Regalis, the Ferruginous Hawk F erruginous Hawks are the largest of the hawks soaring in North America. The adults are heavy, thick-set birds with broad powerful wings. Ferruginous and Rough-legged Hawks are the only hawks whose legs are feathered down to the toes. Adult female Ferruginous Hawks may be up to one third larger than adult males. Ferruginous hawks have a natural range in colour, from very dark to light.
Ferruginous hawks are birds of open country.
They occur in semiarid grasslands with scattered trees, rocky mounds or outcrops, and shallow canyons that overlook open valleys. They may occur along streams or in agricultural areas in migration. Ferruginous hawks rely primarily upon rodents found in their grassland ecosystems. Other prey includes snakes, lizards, meadowlarks, grasshoppers, and crickets. Again, in southeastern Utah prairie dogs seem to be the main prey source.