This is a Harris Hawk. The Harris Hawk is a medium size long leg raptor. They are indiginous to the southern states of North America. Harrises are a social bird and reularly hunt together in packs.
In their wild state, harrises take a wide variety of prey including reptiles, small mammals, rodents and small birds.
The Harris Hawk is used in falconry because they are inexpensive and get along with other Harrises in captivity. This Harris lives in captivity and has a GPS unit attached to his leg. The falconer releases the hawk into the wild to hunt and to use his other skill. Most of the time the hawk returns to his owner. The falconer is able to locate the bird by following the GPS signal if the hawk gets lost or just refuses to return.
A falconer is usually a person who has a license or permit to own a wild bird of prey. The falconer I know is very good about keeping the birds captive and also allowing them to be free in their natural environment for the purpose of hunting and exercise.