The Peregrine Falcon (Falco peregrinus), also known as the Peregrine, and historically as the "Duck Hawk" in North America, is a cosmopolitan bird of prey in the family Falconidae. It is a large, crow-sized falcon, with a blue-gray back, barred white underparts, and a black head and "moustache". It can reach speeds over 320 km/h (200 mph) in a stoop, making it one of the fastest creatures on the planet. As is common with bird-eating raptors, the female is much bigger than the male. Experts recognize 17 to 19 subspecies which vary in appearance and range; there is disagreement over whether the distinctive Barbary Falcon is a subspecies or a distinct species.