3.1) Bornean orangutan (Pongo pygmaeus)
Occurs in Central Kalimantan (Indonesia) and Sabah (Malaysia), with smaller populations in West and East Kalimantan and Sarawak (Malaysia). By 2004, the area of Bornean orangutan habitat remaining was around 86,000 km2 in total, supporting 45,000 to 69,000 individuals in total.

3.2) Sumatran orangutan (Pongo abelii)
Occurs to the north of Lake Toba on the Indonesian island of Sumatra. The most viable populations are found in the Leuser Ecosystem of Aceh and North Sumatra (the large landscape within which is set the Gunung Leuser NP), particularly in the coastal swamps and certain lowland parts of the Alas Valley. The latest population estimate for 2001-2002, as indicated in the World Atlas of Great Apes And Their Conservation, is 7,334 individuals.