erruginous Hawk
This bird is native to North America and not a traditional bird in European or Middle Eastern falconry as it does not exist in the wild in Europe, but it has been very successfully used for falconry. This bird is larger than the Red-tail, and less suited to the variety of prey than the Red-tail will take. It is a more powerful bird and is the strongest and swiftest of the open country buteos, but has smaller feet for its size than a comparable Red-Tail. As such, this is a far less common bird in falconry in part due to the suitability, and in part because it is not as widely available with as high of populations. The Ferruginous hunts small rodents, mice, voles, snakes, and even rabbits in the wild, but will hunt just about anything if the opportunity arises. Because of their large size, they are great birds for hunting rabbits as they can get through even deep brush and have the physical size to catch and hold rabbits. This is an under-estimated hunting companion.
Plumage
The Ferruginous Hawk is sometimes confused with the Red-Tail Hawk. The Ferruginous Hawk does not have the belly band, reddish leggings, or the dark patagial marks.
Morphology
The body form of the Ferruginous is marked by a large body, broad wings, broad (relatively short) tail. One unique characteristic of this bird is the very large mouth. When viewed, it almost looks like the bird is smiling, or like a Red-Tail with an unusually large mouth. The Ferruginuous Hawk also has completely feathered tarsi like the Rough-Legged Hawk and the Golden Eagle.
Hunting
Typical quarry caught with the Ferruginous will be cottontail rabbits, jack rabbits, and other large prey. These birds are the equivalent of cargo planes - large with lots of momentum and power, but unable to be as maneuverable or quick as smaller birds. In the wild it hunts in a style similar to a Red-Tail at times showing the same perching and slow, lumbering flight, however it will also hunt similarly to a Marsh Hawk. These birds frequently hunt in pairs.
Trivia
This bird has also been called the Eagle Hawk, the Gopher Hawk, and the Squirrel Hawk. These birds are commonly referred to as "ferrugies". The term for the female Ferruginous is much debated as there is no traditional term, although "hen" is generally not accepted. The male is generally called a "tiercel". It is the largest North American hawk.
These hawks have feathered legs.
Due to the large mouth opening, these birds are difficult to find good fitting hoods for.
The Ferruginous lays up to 6 eggs per clutch. The size of the clutch appears to be directly related to the local ground squirrel population. It nests on the ground or a broad ledge, and infrequently will choose a tree.
These birds are on the rise with an estimated 6,000 to 14,000 in the US alone.
Links
http://www.desertusa.com/mag00/feb/papr/hawk.html