Modern orangutans originated during the Pleistocene period, 2 million to 100,000 years ago. 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.
- Fossils from a million years ago indicate that there were giant sized orangutans in Indochina.
- Adult male orangutans will make a booming long call several times a day, that along with a number of possible functions, keeps subordinate males away.