Together with the chimpanzee (Pan troglodytes), the bonobo is man's closest living relative (2). Although a similar size to the better-known chimp, the bonobo is often referred to as the pygmy chimpanzee due to the more slender body shape of this species. Like chimpanzees, bonobos have longer forearms than legs, long fingers and mobile shoulder joints. The coat is black although it may turn grey with age and, in contrast to chimpanzees, the face is black, and the hair on the crown projects sideways, as opposed to backwards (2) (3).