The Pallid Falcon Falco kreyenborgi Is a Color Phase of the Austral Peregrine Falcon (Falco peregrinus cassini)

Abstract The Pallid Falcon (Falco kreyenborgi), a rare form from southern Patagonia and Tierra del Fuego, has, since its discovery in 1925, gained acceptance as a full species. In 1981, we observed 13 Pallid Falcons on the Patagonian Steppe. Four adult Pallid Falcons were paired with normal Peregrine Falcon (Falco peregrinus cassini) mates. Two normal-phased peregrine pairs produced mixed broods of normal and pallid young. One pair of pallid adults produced only pallid young. These observations lead to the conclusion that the Pallid Falcon is conspecific with and a color phase of the Peregrine Falcon.