The siamang (Siamanga syndactyla) is a great ape peculiar to the island.
The later stages of evolution leading from his ape-like ancestors to man have consisted definitely in the acquirement of a larger and therefore more educable brain by man and in the consequent education of that brain.
The celebrated ape "Mafuka," which lived in the Dresden zoological gardens during 1875, and came from Loango, was apparently a member of this species, although it was at one time regarded as a hybrid between a chimpanzee and a gorilla.
Bachian is remarkable as the most eastern point on the globe inhabited by any of the Quadrumana, a black ape occurring here as in Celebes.
In Borneo the red ape inhabits the swampy forest-tract at the foot of the mountains.