A small, stocky bird with short wings, a short tail, and strong legs that hunts for small animals in fast-flowing streams, perching on a rock and making the bobbing motion that gives it its common name, then walking or diving into the water and foraging on the stream bed. There are five species in the genus Cinclus, the only genus in the family Cinclidae, found throughout North, Central, and South America, Eurasia, and in the Atlas Mountains of Morocco.