Orangutans are the only great apes native to Asia. The three other types (gorilla, chimpanzee, and bonobo) are found in Africa. Less than 20,000 years ago the orangutan could still be found all over Southeast Asia, from Java in the south to the Himalayas and southern China in the north. Today this great ape can only be found in Sumatra and Borneo (Kalimantan), 90% of it is located within Indonesia (Figure 1). This substantial habitat loss is primarily caused by competition with humans, especially since both orangutan and human share a land preference for alluvial plains along major rivers and peat swamps. Human invasion into these area for social, economic, and cultural development frequently has fatal consequences to the orangutan.