In all diumal birds of prey (especially falcons) age can be determined by the color of the feet, eye rings and cere. This difference is especially evident in juvenile birds. Typically up to their second year, young Prairie Falcons have a bluish gray or bluish green colored cere, eye ring and feet, which turn a bright orange-yellow color once they reach adulthood. One other factor which can determine skin color is nutrients in the diet. Captive birds lacking in potassium lose the bright yellow glow in the legs, cere and other exposed areas. Color morphism also can play a role-young hawks and falcons tend to wear a mottled "cryptic coloring" of muted brown and tan and have longer primary and tail feathers than adults.

Prairie Falcons were, of course, unknown to medieval falconers, but the species is rather popular among modem falconers, in spite of its volatile and often unpredictable temperament. Whereas Peregrines are generally calm in nature and among the easiest falcons to train and maintain, the personalities of most Prairie Falcons often push to the limit the patience of many novices.

Prairie Falcons are extremely persistent in the chase and will even follow their quarry into heavy cover on occasion, in much the same manner as the accipiters, although with much less agility on the ground due to their shorter legs.  I once had a female Prairie Falcon that I flew almost daily for nearly ten years.  She would often follow pigeons into barns, being so determined; a Peregrine would have stopped short.  For six days of the week, she was the ideal bird-we understood one another. But on the seventh, she might suddenly throw a fit and become temporarily unmanageable.

Prairie Falcons, like Gyrfalcons, generally do not fly as high as Peregrines when hunting.  But they are just as fast and even a bit more maneuverable on the wing due to the shorter wings and longer tail. They take much of their prey on the ground, and must dodge obstructions. They are more inclined to take ground squirrels and other desert rodents, and have even been observed walking around on the ground eating large insects.  Their overall color matches the sandy brown of the desert perfectly.

Like the Peregrine and Gyrfalcon, the Prairie Falcon usually chooses a nest site on a cliff face with a protective overhang, and its nesting chronology is similar to the Peregrine. Some years ago, I spent several weeks photographing the home life of a pair of Prairie Falcons for Audubon Magazine in Oregon's Great Sandy Desert. The site itself had been in use for many years, judging from the great accumulation of droppings around it. The chicks were about two weeks old when we erected a tower and blind on the talus slope about 25 feet from the eyrie.  The male was providing all of the food, nothing but Townsend's ground squirrels, while the female would do little else except stand guard on a favorite rock above the nest.

For the first few days, I was puzzled by the fact that the male would deliver the food each morning so quickly, usually four ground squirrels, one after another in just a couple of minutes. We soon discovered the reason. He would go hunting early and, one by one, cache the first three kills. After the fourth, all were brought to the nest in rapid succession, where the female accepted the booty and began feeding the young. It has often been stated that birds can't count, but it seemed this one could: there were four young falcons in that nest.

Length:  17 to 20 inches