The Crested gibbon (Hylobates concolor) is one of five species of the Gibbon family. Gibbons are also called "lesser apes", indicating their close relationship to the "great apes", including Chimpanzees, Bonobos, Gorillas and Orang-utans. This means that Gibbons are also quite closely related to man. They inhabit rainforests of South-East Asia. Crested gibbons - like the other Gibbon species - live in family groups, consisting of an adult pair and their young. The female gives birth to a single young all two to three years. The young Gibbon stays with the group for several years. Thus different aged young, mostly two to four, belong to the family. The group migrates within its territory, in order to get enough of their prefered food - fruits, which are distributed in a dispersed way. Very special with Crested gibbons is the different colour of the genders. The male and the young are of black fur colour, whereas the female is bright brown. This sexual dimorphism is quite unusual concerning Gibbons. In the other Gibbon species males and females are quite similar, which is common with animals that are living monogamous.