The most obvious way to discern a cockatiel from other cockatoos is the size difference. Cockatiels are about half the size of other cockatoos and have much smaller beaks. In the wild, cockatiels are gray with yellow and orange faces, although some variations of color exist and are more common in captivity. Most cockatoos are solid white or black, but some have yellow, red and pink as well. In all cockatoos, which includes the cockatiel, color variations exist according to gender, with males being more brightly colored.