Vocalizations appear to dominate the Muna-Buton macaque communication system. Males and females have unique alarm calls, barks, and screams. Coos, whines, and squeaks are common in babies and young.

Agonistic (aggressive) screams are emitted by both males and females, which almost always trigger a physical, locomotive response by other troop members. Described as a loud whoop, it is the Muna-Buton macaque’s most distinctive call. In males, only the alpha emits this call—being the highest pitch of their vocal repertoire and traveling the furthest—typically used when sighting danger or another troop.

Females use interval screams as their alarm calls. The calls grow longer as the sequence increases in length. This is also a loud woop and their highest pitch. Compared to males, however, it lasts longer and travels farther. Additionally, it may also be used to coordinate groups.

When peeved by another individual, Muna-Buton macaques will tell them to back off using an aggressive bark. Depending on the level of annoyance, anger, or warning, barks become throatier—almost sounding like a cough. This can mean anything from “back away from my food,” “you’re too close to me,” or  “I don’t want to play.” Roughness and fights may break out, and coughing intervals decrease during this time but still emerge amidst the scuffle.

Babies have a very simple distress call: a long, high-pitched squeak. This lets others know that they need attention, or their family has veered too far away for their liking.

In daily life, primary vocalizations are made up of “coo calls.” Frequently used, they are low, soft, short barks used for troop cohesion or to alert others that the group has spread too thin and needs to be reunited.