The orangutan (Pongo pygmaeus) is the only strictly arboreal ape and is actually the largest tree living mammal in the world. The rest of the apes do climb and build sleeping nests in the trees, but are primarily terrestrial (spending their lives on the ground). Even the hair color of the orangutan, a bright reddish brown, is unique in the ape world. Theyare highly intelligent with an ability to reason and think. This large, gentle red ape is one of our closest relatives, sharing 97% of the same DNA as humans. Indigenous peoples of Indonesia and Malaysia call this ape Orang Hutan literally translating into English as People of the Forest.
Modern orangutans originated during the Pleistocene period, 2 million to 100,000 years ago. In a recent discovery (reported in 2002), a team of scientists unearthed a fossil ape (Lufengpithecus chiangmuanensis) in Thailand dating back 10 to 13.5 million years ago. It consists of both an upper and lower jaw with similar dental structure as today's orangutan and they consider it to be an ancestor of the new form. This discovery would place the development of the earlier orangutan in a similar habitat as today's tropical forest home on Sumatra and Borneo. More fossils need to be found and studied to complete the picture of its evolutionary history.
Orangutans have four hands instead of two hands and two feet. This makes them graceful and swift while swinging through the trees but it makes walking on the ground very slow and awkward. That is why the orangutan is at a great disadvantage on the ground, and why the orangutan rarely comes down from the treetops. Their food is there, their home is there and they are safer there. An orangutan's lifespan is about 35-40 years in the wild, and sometimes into the 50's in captivity. They reach puberty at about 8 years of age, but a female isn't ready for her own baby until she's in her teens.
They now face extinction. At the turn of the last century around 315,000 orangutans existed in the wild. Orangutan numbers are now down by 92% compared with a century ago and have been reduced by half in Northern Sumatra between 1993 and 2000. Today, the orangutan is found only on the islands of Borneo and Sumatra in scattered populations. They can be found on Kalimantan (west, east and central Kalimantan), Malaysian Borneo (Sarawak and Sabah) and northern Sumatra. The types of forest include tropical montane, lowland dipterocarp, peat swamp and heath. The highest densities are in the swamp forests. The population of orangutans in their natural habitats has fallen dramatically over the past two decades. Recent estimates place the numbers at between 10,000 and 15,000 in Kalimantan and from 5,000 - 9,000 in Sumatra.
Damaging their habitat, the illegal hunting and trading of young orangutans has reduced the orangutans population while at the same time many environmental and man-induced factors have resulted in more and more infants than ever being abandoned or mistreated. Therefore, orang-utans have to be saved, protected and preserved. In order to safeguard and protect the orang-utan and other wildlife species in Indonesia, since 1978, the Directorate of Nature Conservation and Wildlife Management (Direktorat Perlindungan dan Pengawetan Alam, or PPA as abbreviated), has set the target of designating about 10% of land as preserved areas. There are at present 320 natural reserves and natural parks in Indonesia, and more are proposed. PPA has adopted the modern natural conservation practice, which emphasizes the conservation of the entire ecosystem. This is necessary as it is often not possible to preserve wildlife without its habitat.