Peregrine Falcon

The peregrine falcon, also known as the peregrine, and historically as the duck hawk in North America, is a widespread bird of prey (raptor) in the family Falconidae. A large, crow-sized falcon, it has a blue-grey back, barred white underparts, and a black head. The peregrine is renowned for its speed, reaching over 320 km/h (200 mph) during its characteristic hunting stoop, making it the fastest bird in the world, as well as the fastest member of the animal kingdom. According to a National Geographic TV program, the highest measured speed of a peregrine falcon is 389 km/h (242 mph). As is typical for bird-eating raptors, peregrine falcons are sexually dimorphic, with females being considerably larger than males. According to one study, it has the fastest visual processing speed of any animal tested so far, and can register discrete changes up to 129 Hz or cycles per second. Analogically, film is a series of still images projected onto a screen. Those still images need to be changing at roughly 24 frames per second before humans see them as fluid and no longer as individual, discrete pictures. The film would have to be refreshing at 129 frames per second before peregrine falcons stopped seeing flashing, still images and started seeing fluid motion.