… are arboreal apes that live in Indonesia, Malaysia, and Thailand. The most distinguishing characteristic of these primates is the enlarged throat sac that can be as big as a human head! This throat sac is used as a sound box to amplify their loud vocalizations.
Siamangs are territorial and interact with other family groups through loud calls that let other groups know where their territory is. Mated pairs also perform complex duets, producing loud, well-patterned calling bouts that advertise the presence and status of a mated pair.