Orangutans Known for their distinctive red fur, orangutans are the largest arboreal mammal, spending most of their time in trees. Long, powerful arms and grasping hands and feet allow them to move through the branches. These great apes share 96.4% of our genes and are highly intelligent creatures. The Malay word orangutan means “person of the forest.” These long-haired, orangish primates, found only in Sumatra and Borneo, are highly intelligent and are close relatives of humans.

Adult males also have a throat pouch that serves as a resonating chamber for the “long call,” a sequence of roars. Males typically vocalize for a minute or more, calls up to five minutes in length. Females virtually never give the full sequence of the long call, as it serves to space males and attract sexually receptive females. Otherwise, orangutans are generally silent.