Ferruginous Hawk

The Ferruginous Hawk (Buteo regalis), a majestic bird of prey, is the largest of the North American Buteos. Its regal bearing and impressive size often lead to it being mistaken for an eagle. The species exhibits a striking rust-colored or "ferruginous" plumage in its light morph, while the dark morph presents a more uniform dark brown coloration. Both morphs have feathered legs extending to the talons, reminiscent of the Rough-legged Hawk.

Identification Tips

The Ferruginous Hawk is characterized by its large size, broad wings, and a wide tail that comes in shades of gray, rusty, or white. The light morph has a rusty back and pale underparts, with gray upper wings. The dark morph is uniformly dark brown with lighter areas on the wings. In flight, the species can be identified by its dihedral wing posture and the "V" shape formed by its dark legs against a lighter underside. The rufous rump mark is a distinctive feature when the bird is soaring.

Habitat

This hawk favors the open, arid grasslands, prairies, and shrub steppe regions of interior North America. It thrives in environments that are level or rolling and largely devoid of trees, such as foothills and plateaus. During breeding, it prefers grasslands and sagebrush areas, avoiding cultivated fields.

Distribution

Endemic to North America, the Ferruginous Hawk's range spans from the southern reaches of Canada through the western United States into northern Mexico.

Behaviour

The Ferruginous Hawk exhibits an active flight pattern with slow, fluid wingbeats akin to a small eagle. It soars with wings held in a dihedral or glides with wings flat. Hunting techniques include hovering, low cruising, and high soaring, with the bird often perching on elevated sites to scan for prey.

Song & Calls

The vocalizations of the Ferruginous Hawk are not well-documented but include a "kree-a" or "ke-ah" alarm call and harsh "kaah" calls, similar to those of the Herring Gull. Some descriptions also mention "wavering" calls and "breathy" notes.

Breeding

Copulation coincides with nest building, with egg-laying varying by latitude and environmental conditions. Both sexes share incubation duties over an average period of 32 days. Nesting sites are diverse, including trees, ground, and man-made structures. Clutch sizes range from one to eight eggs, with an average of three to four.

Similar Species

The Rough-legged Hawk (Buteo lagopus) is similar in appearance but can be distinguished by its darker coloration, black tail band, and chest band. The Red-tailed Hawk (Buteo jamaicensis) is also similar but has a darker underwing and lacks the rufous rump mark of the Ferruginous Hawk.

Diet and Feeding

The diet is predominantly small to medium-sized mammals, with rabbits, hares, ground squirrels, and pocket gophers being major food items. Birds, reptiles, and insects supplement the diet. Hunting strategies include perch and wait, low-level flight, and cooperative hunting.

Conservation status

The Ferruginous Hawk is currently listed as Least Concern by the IUCN, with recent population increases and conservation efforts contributing to a more optimistic outlook for the species. However, habitat loss and reductions in prey due to agriculture remain concerns for its long-term conservation.