Nest Characteristics of the Sumatran Orangutan () in the Wildlife Sanctuary Soraya Station in Aceh Province, Indonesia.

Orangutans ( spp.) populations used to be widely distributed throughout Southeast Asia, from Java in the south to the Southern China in the north during the Pleistocene. Their populations have declined up to 75% of their original size and are now distributed only in parts of the tropical rainforests of Borneo and Sumatra.