National Geographic : 1994 Dec
Animals AT Play BY STUART L. BROWN It looks like a fight as a pair of two-year-old lions from the same pride in Kenya confront each other (right). But although they seem to snarl, their teeth are not exposed, and their body language is more balletic than aggressive. They are merely playing at fighting. In Sumatra an orangutan hanging upside down to take a drink decides that the river is entirely too much fun just for drinking. Adults and young, alone and together, mammals and many birds play-but why? Do they gain anything from these exuberant displays, or do they do it just because it feels good?