Macaca brunnescens

Geographic Distribution and Habitat

The Muna-Buton macaque (Macaca brunnescens), also referred to as the Muna-butung macaque or the Buton macaque, is found in the Indonesian islands of Buton and Muna. Located southeast of the Sulawesi peninsula, these islands are made of sandy beaches, rolling limestone cliffs, and dense forests—a truly breathtaking tropical paradise to call home. Muna-Buton macaques occupy a home range of ~0.24 miles (62 ha), inhabiting everything from the salty coasts and lush primary forests to subtropical moist lowlands and rich mangroves.


The Muna-Buton macaque is one of seven Sulawesi macaques in Indonesia.

The Muna and Buton islands separated from Indonesia only 10,000 years ago. This may seem like a long time to us, but some scientists argue this is too short a period to consider the Muna-Buton macaque a unique species. They suggest that they are actually booted macaques, Macaca ochreata, or a subspecies of the booted macaque. 

Muna-Buton macaque range, IUCN 2023

Size, Weight, and Lifespan

Males have an average head and body length of 19 inches (48.5 cm); females, 16.6 inches (42 cm). Although not quite two feet long, males can weigh between 31-37 pounds (14-16.8 kg). Females are about half this size averaging 16 pounds (7.3 kg). All Sulawesi macaques have very stubby tails—for the Muna-Buton macaques, theirs is only about 1.3 inches (3.3 cm) long.   

Their age and lifespan have not been recorded. Other Sulawesi macaques, such as the Tonkean macaque, can live up to 28 years in captivity.


Dark gray or black dense, woolly fur covers Muna-Buton macaques’ bodies. Sometimes, trails of a brownish hue can run along their back. Beneath their chin, they have a light gray throat patch, with the same color also appearing on the lower region of arms and legs to give them the appearance of wearing “boots”. Individuals from Muna are slightly lighter in color than those from Buton.

Muna-Buton macaques have relatively large heads for their size and dark hairless faces shadowed by a heavy brow. Large, soulful eyes—usually amber or shades of brown—a long nose, and flat nostrils rest above their pouty mouth.

Appearances gradually change as the Muna-Buton macaque ages, especially in terms of color. Youngsters and adolescents have the darkest coats that lighten as they mature. As their age progresses, older individuals gray drastically, which sometimes can be a full-pelage transformation.

Photo: © Panji Gusti Akbar/iNaturalist/Creative Commons

As avid fruit lovers, a succulent variety of figs, papaya, banana, and pandanus fruits make up over 60% of the Muna-Buton macaque’s diet. Seeds, young and mature leaves, flowers, bark, and insects are also noshed throughout the day.

Muna-Buton macaques are also fans of agricultural offerings. In farmer’s eyes, they are pests. Groups with access to cultivated crops will raid areas for sweet potatoes, maize, cacao, and fruits. Data indicates raiding populations source up to 24% of their diet from cultivated crops, which causes high tension with local farmers.

Behavior and Lifestyle

Researchers are still gathering details and data regarding Muna-Buton macaques. What we do know is they are active during the day and rest during the night, otherwise known as being diurnal. They are quadrupedal and typically spend equal time arboreally and terrestrially—however, in areas close to human settlements, they have been reported to spend more time on the ground. Opportunities for scavenging snacks may be the reason this behavior shifts.

Fun Facts

Sulawesi macaques have incredibly short tails! Roughly an inch in size, some people mistake these monkeys for apes.

Daily Life and Group Dynamics

Muna-Buton macaques are constantly on the move. Driven primarily by finding their next tasty meal, they spend 43% of their time clambering about and moving between feeding sites. Once they have found an opportunity or appealing menu selection, they will hunker down and feed, followed by either grooming or resting before they stir again for their next meal. Feeding takes up 21% of their day, grooming 10.5%, and resting 17%. Groups that forage agricultural sites move around less and rest more—extensive travel isn’t needed when you aren’t foraging to find your next meal. Their leisure and downtime take up 32–38% of their day. Life is easier when you have access to your local farmer’s market—even as an unwanted customer!

Group dynamics are steered by a relaxed matrilineal system (based on kinship with the mother or female line) of dominance. Anywhere from 20-36 individuals can live together and are referred to as a troop. They have one alpha male and overall, are considered a tolerant species.


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.

Reproduction and Family

Little is known about the reproduction and family dynamics of Muna-Buton macaques. We do know their babies are usually born between May and September, but other than that, we can look to other species of Sulawesi macaques to hypothesize reproductive patterns. Their close cousins, Tonkean macaques, are more well-studied and can offer similar habits and traits. Their males become sexually mature between the ages of 4 and 5 and females at the age of 3. Gestation (pregnancy) is 173 days, after which the mother births a single baby. She cares for her young with deep emotion. Upon maturity, males leave their natal groups to start their own families.

Photo: © Panji Gusti Akbar/iNaturalist/Creeative Common
Ecological Role

As fruit eaters, the Muna-Buton macaque can scatter seeds of various species through their feces. Knowing their home range of ~.24 miles (62 ha), it can be assumed that this is their cultivation and “gardening” zone—whether intentionally or not! As the rainforests of Muna and Buton suffer from deforestation, every little bit counts to uphold plant abundance and diversity.

Conservation Status and Threats

The International Union for Conservation of Nature lists the Muna-Buton macaque as Vulnerable (IUCN, 2015), appearing on the IUCN Red List of Threatened Species.

The population decline is expected to wane by 30% over the next three generations (33 years). Farming, logging, mining, and human settlements are drastically reshaping the islands of Muna and Buton, causing an upheaval of the Muna-Buton macaque’s habitat. Once widespread across both islands, Muna is now only populated by small pockets of macaque groups or within protected areas, with the majority residing on Buton. Illegal and legal logging are specifically making it hard for this species to thrive. Deforestation is almost completely unchecked by laws and sustainable focuses.

Conservation Efforts

This species is listed under the Convention on International Trade in Endangered Species (CITES) Appendix II.

Little is known about ongoing efforts to protect the Muna-Buton macaque aside from the opportunity for refuge in protected areas. It is speculated the largest populations in protection forests, limited protection, and standard production forests reside on Buton. The Kakenauwe Nature Reserve and Lambusango Wildlife Reserve on Buton are two primary areas that host the Muna-Buton macaque.  

Past attempts have been made to study sample sizes and populations with little success. Researchers suggest that studies and population surveys should be carried out given the scarce data regarding their population. Their proposals challenge others to determine the minimum amount of space needed for conservation, a protected areas management plan, and refining a species action plan.

The World Travel Index cites that Buton is moderately equipped as a destination site and a low risk for over-tourism. While this is good news amidst Indonesia’s rising travel popularity, it may not always be the case as time progresses. Now is the time to rally government and stakeholders to shape positive models of ecological and conservation tourism. Solutions may include furthering education and spreading awareness of the importance of saving Muna-Buton macaques and using this to create sustainable traction to protect their home.


Written by Dana Esp, March 2024