Orang-utan means 'person of the forest' (4) and this Asian ape is indeed truly a tree-dweller. Recent genetic evidence has led to the re-classification of Bornean and Sumatran orang-utans as separate species: Pongo pygmaeus and Pongo abelii respectively (5). Orang-utans have distinctive body shapes with very long arms that may reach up to two metres in length. They have a coarse, shaggy reddish coat (6) and grasping hands and feet (2). They are highly sexually dimorphic, with adult males being distinguished by their large size, throat pouch and flanges on either side of the face, known as cheek pads (7).