Many animals engage in “play,” that is, activities that enhance learning of motor and sensory skills and social behaviors but otherwise serve no immediate purpose. Young screech-owls pounce at leaves; young crows and jays pick up, inspect, and hide all kinds of shiny objects; young gulls and terns carry small items aloft and drop them, catch them in midair, and drop and catch them again. All these activities probably help birds acquire the skills and coordination they’ll need for hunting and other essential activities as adults.
Some forms of play, called “locomotor play,” seem quite similar to the exhilarating play of children sledding down a steep hill. Some ducks have been observed floating through tidal rapids or fast-moving sections of rivers, and when they’ve reached the end, hurrying back to the beginning to ride over and over.