Communication and Perception
Bornean orangutans have a vocal repertoire of about 13 sounds. Within a small social group they communicate with lip smacking. They scream when scared, and males sometimes roar. They seem to grind their teeth when frustrated. Males also emit a long series of loud groans, which can be heard by a human up to 1 kilometer away. This vocalization may serve to space males apart.
In addition to vocal communication, tactile communication is used by these animals. Social grooming is an important activity in all primates. Facial expressions, gestures, and body postures are also used to communicate.
Communication Channels: visual ; tactile ; acoustic
Perception Channels: visual ; acoustic