Hawks Aloft, Inc.
Conservation, Avian Research, and Education
PO Box 10028 - Albuquerque, NM 87184 - (505) 828-9455

 

Ferruginous Hawk (Buteo regalis)

 Field Marks:

            -  length: 21 in.  wingspan: 56 in.

            -  largest of the soaring hawks

            -  white belly and underwing with small rufous specks

            -  adults have a rufous “V” formed by dark leg feathers on the underside while in flight

            -  rufous back, white head and tail

 Breeding Range:

Ferruginous Hawks breed in western North America from southern Canada to mid-New Mexico. 

 Wintering Range:

Ferruginous Hawks winter from northern Colorado to mid-Mexico.  Northern populations begin migration in September-October, and return in March or April. 

 Habitat Preferences:

They inhabit large flat expanses of juniper savanna and grassland.  They do not utilize forested areas or narrow canyons, but are found on the borders between pinyon-juniper forests and open grassland.  

 Nesting:

They are monogamous for the life of the pair.  They often reuse the same nest as previous years.  Nests are usually on a lone juniper or deciduous tree, rock spire, or man-made structure such as a windmill or power pole.  The average clutch size is 2-4 eggs, but ranges from 1-8, depending on prey abundance.  The young leave the nest after 38-50 days after hatching, but remain near the nest for several weeks.  The young begin killing prey at 52 days after hatching.

 Feeding:

The Ferruginous Hawk’s diet consists primarily of rabbits, squirrels, and prairie dogs.  They employ the “sit and wait” technique when hunting, and often sit on power poles or even on top of prairie dog mounds waiting for a prairie dog to emerge.  During this hunting technique, hawks lay on their side or back with their feet extended near the burrow exit.  The sounds made by a prairie dog prior to emergence from a burrow alerts the hawk.  The hawk then grabs and kills the prairie dog with its talons. 

 Conservation Status:

Although there have been reports of declining populations, due to their nomadic nature, accurate population numbers are not available.  Ferruginous Hawks are highly susceptible to human disturbance, especially during the breeding season.  Individuals may abandon nests with viable eggs or young if disturbed at any time during the breeding process.  The Ferruginous Hawk was proposed for federal listing in 1991.  That petition was declined, in part, due to a lack of sufficient population estimates.  The Ferruginous Hawk is protected under the Migratory Bird Treaty Act, and is listed as a sensitive species by the Bureau of Land Management.