Stump-tailed macaques have cheek pouches that, when filled, can hold a volume equal to that of their stomach. They forage starting in the morning through midday. They are omnivorous, but they eat mostly fruit. They also eat seeds, flowers, roots, leaves, and animals such as frogs, freshwater crabs, birds, and bird eggs. They have also been known to raid corn crops and cultivated fruits.
Animal Foods: birds; mammals; amphibians; reptiles; eggs; insects; terrestrial worms; aquatic crustaceans
Plant Foods: leaves; roots and tubers; seeds, grains, and nuts; fruit; flowers
Foraging Behavior: stores or caches food
Primary Diet: herbivore (Frugivore ); omnivore
Potential predators are large raptors, common leopards, dogs, and clouded leopards. To deter predators, they shake branches, bare their canines, assume aggressive postures, and alpha males will "roar".
Known Predators:
Stump-tailed macaques, also known as bear macaques, have shaggy, dark brown hair covering them. They have hairless faces with red skin which darkens with sun exposure. Infants are born with white hair that darkens as they age. As they age, adult males and females show balding on the tops of their heads, much like human males, receding from the forehead towards the back of the skull. As in all other cercopithecines, they have cheek pouches that they use to store food when foraging. They are terrestrial quadrupedal movers.
Stump-tailed macaques have hairless tails that are shorter than other g.Macaca species. Tail length ranges from 3.2 to 69 mm. This species is sexually dimorphic in many aspects of their physiology. Males are larger, ranging from 9.9 to 10.2 kg and 517 to 650 mm in height whereas females are 7.5 to 9.1 kg and 485 to 585 mm in height. Males also have much larger canines, which they use for asserting dominance within their group. Like all cercopithecids, they have a dental formula of: 2/2, 1/1, 2/2, 3/3.
Range mass: 7.5 to 10.2 kg.
Range length: 485 to 650 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
They can live up to 30 years in captivity. However, they tend to have shorter lifespans in the wild.
Average lifespan
Status: captivity: 30 years.
Stump-tailed macaques are found in subtropical evergreen forests below 1500 m and tropical evergreen rainforests between 1800 and 2500 m. They live in wet environments and are not found in dry forests.
Range elevation: 2500 (high) m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: forest ; rainforest
Stump-tailed macaques are native to southeast Asia. Their distribution includes China, India, Burma, West Malaysia, Thailand, Vietnam, eastern Bangladesh, and the Malay Peninsula. There is an introduced population in Tanaxpillo, Veracruz, Mexico, an island not inhabited by humans, where they live in conditions similar to their natural habitat in Asia.
Biogeographic Regions: nearctic (Introduced ); palearctic (Native )
Stump-tailed macaques contribution to native ecosystems as seed dispersers.
Ecosystem Impact: disperses seeds
Humans have used stump-tailed macaques for testing the anti-hairloss drug minoxidil also known as Rogaine. By testing on the macaques, researchers were able to produce a safe product for human use.
Positive Impacts: research and education
Stump-tailed macaques can be a nuisance for farmers by crop raiding.
Negative Impacts: crop pest
On the IUCN list stum-tailed macaques are considered vulnerable. They are at risk for extinction in the near future. Their populations have decreased 20% in the last 10 years. There have already been instances of certain populations disappearing. Indian and Bangladesh populations haven't been seen since 1990. Habitat and hunting are the main causes and concerns for their conservation. They are also becoming more uncommon in Thailand and Malaysia. Human induced habitat change is the primary cause of population decline. Urban and agricultural expansion threatens native habitats. In India, where these macaques are legally protected, they have set aside areas of land for stump-tailed macaque conservation and are enforcing protection.
US Federal List: threatened
CITES: appendix ii
State of Michigan List: no special status
IUCN Red List of Threatened Species: vulnerable
They communicate mostly visually and vocally. Common forms of visual communication are "teeth chattering", presenting one's rump to another individual, "lip smacking" and "barred teeth". When in heat, the females have swellings on their behind. This is a form of sexual communication, that they are receptive to mating.
Vocal communication often consists of "coo" which is used to stay in contact with other group members or when approaching another individual. They also use grunts when approaching another after fighting or if they are interested sexually. As mentioned before alpha males will "roar" to fend off predators.
When infants are distressed they will let out a shrill "whistle".
Communication Channels: visual ; tactile ; acoustic
Other Communication Modes: pheromones
Perception Channels: visual ; tactile ; chemical
Stump-tailed macaques are promiscuous in their mating behavior. Dominance plays a big role in who gets to mate. High ranking males monopolize females in the group. However, lower ranking males have other strategies of obtaining mating opportunities. They hang back and mate with females when the dominant male is not watching. Often referred to as the "sneaker" male strategy.
Both males and females initiate mating, though males tend to be more active when it comes to sexual behavior. Females make eye contact and present their perineal region (rump). Males approach females and sit next to them. Males chatter their teeth and grimace. When copulation is occurring, other group members often harass the pair.
Mating System: polygynandrous (promiscuous)
In their native habitat, stump-tail macaques breed during the months of October and November. In captivity they don't reproduce on any seasonal schedule. Females have an offspring about every 2 years. The gestation period is 177 days. After birth, infants are nursed for 9 months. After weaning they are still dependent on their mother and other adults in the group and don't reach independence until about 1.5 years old.
Young inherit rank maternally as females are philopatric. Male young disperse sometime after independence.
Breeding interval: Stump-tailed macaques can reproduce about every 2 years.
Breeding season: Breeding occurs in October and November in wild, Feburary and March in the introduced Mexican population.
Average number of offspring: 1.
Average gestation period: 177 days.
Average weaning age: 9 months.
Average time to independence: 18 months.
Average age at sexual or reproductive maturity (female): 4 years.
Range age at sexual or reproductive maturity (male): 4.5 to 5 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
The primary caregiver for young is the mother. She nurses, carries, and protects them. Additionally, all the females in the group care for the young of other females, especially if the mother is high ranking. Females carry, play with, protect, and groom the young. Alpha males will also help protect young and infants since there is a good chance they are their offspring.
Stump-tailed macaques are more gentle with their young than other macaque species. Their is no threat of kidnapping from other group members, so mothers tend to be lenient with their young and give them independence in exploring the environment around them.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Male, Female); pre-independence (Protecting: Male, Female); post-independence association with parents; extended period of juvenile learning; maternal position in the dominance hierarchy affects status of young
Website with information on taxonomy, morphology, ecology, behaviour, and conservation of this species.
The stump-tailed macaque (Macaca arctoides), also called the bear macaque, is a species of macaque native to South Asia and Southeast Asia. In India, it occurs south of the Brahmaputra River, in the northeastern part of the country.[3] Its range in India extends from Assam and Meghalaya to eastern Arunachal Pradesh, Nagaland, Manipur, Mizoram and Tripura.[4]
It is primarily frugivorous, but eats many types of vegetation, such as seeds, leaves and roots, but also hunts freshwater crabs, frogs, bird eggs and insects.[5]
The stump-tailed macaque has long, thick, dark brown fur covering its body, but its face and its short tail, which measures between 32 and 69 mm (1.3 and 2.7 in), are hairless.[5] Infants are born white and darken as they mature.[5] As they age, their bright pink or red faces darken to brown or nearly black and lose most of their hair.[5] Males are larger than females, measuring 51.7–65 cm (20.4–25.6 in) long and weighing 9.7–10.2 kg (21–22 lb), while females measure 48.5–58.5 cm (19.1–23.0 in) and weigh 7.5–9.1 kg (17–20 lb).[5] Males' canine teeth, which are important for establishing dominance within social groups, are more elongated than those of the females.[5] Like all macaques, this species has cheek pouches to store food for short periods of time.[5]
This Old World monkey travels quadrupedally, usually on the ground, as it is not very agile in trees.[5] It is generally found in evergreen tropical and subtropical moist broadleaf forests, at different elevations depending on the amount of rainfall in the area.[5] It depends on rainforests for food and shelter, and is not found in dry forests except where it ranges in the Himalayan region of India, only spending time in secondary forests if it is bordering old-growth forest tropical forests.[5] With its thick fur, the stump-tailed macaque can live in cold climates at elevations up to 4,000 m (13,000 ft).[6] It is distributed from northeastern India and southern China into the northwest tip of West Malaysia on the Malay Peninsula.[1][5] It is also found in Burma, Thailand, Laos, Cambodia and Vietnam.[2][5] It is possibly extinct in Bangladesh.[2] No global population estimate is available. In Cambodia, a declining population of 230 is reported from Keo Seima Wildlife Sanctuary.[7][8]
A study population was introduced to Tanaxpillo, an uninhabited island in Lake Catemaco, Veracruz, Mexico in 1974, where it ranges in seminatural conditions.[5] Most information on the species comes from the introduced population on Tanaxpillo and other captive settings, as few long-term studies have been conducted on the stump-tailed macaque in the wild.[5]
Stump-tailed macaque generally share the same social structure of any macaque species with a linear dominance hierarchy that is rigid and hereditary in females yet fluctuates among males based on their fighting ability and social maneuvering, but what makes stump-tail macaques truly unique is their ability to defuse intense confrontations and maintain a high degree of pacifism and harmony in their troop, thanks to their surprisingly rich repertoire of reconciliation tactics.[9] This species has no lasting pair bonds and is truly promiscuous, a staple for macaques. Physical violence very rarely occurs, and although minor scraps often flair up and physical intimidation displays occur, they tend to quickly be resolved, resulting in this species being labelled as peaceful.[10] Stump-tailed macaques are remarkably unfussy in their eating habits though fruit generally is a staple part of their diet. Stump-tail macaques have a large, bulky, muscular build with thick, solid limbs, making them very mobile on land yet quite ungainly in trees, and this unusual physique for a macaque may be responsible for this species unique tendency to consume larger quantities of meat than other macaque species. Stump-tail macaques feed on very large quantities of insects, small animals and eggs.[10]
A study population of female stump-tailed macaques was found to have increased levels of steroid sex hormones, specifically 17β-estradiol and progesterone levels. 17β-estradiol levels were significantly greater during summer and fall and progesterone levels were significantly greater during summer, fall and winter. This explains how stump-tailed macaques have two mating seasons per year: one in summer (July–August) and one in fall (November). This is supported by the distribution of birth frequency in stump-tailed macaques.[11]
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The stump-tailed macaque (Macaca arctoides), also called the bear macaque, is a species of macaque native to South Asia and Southeast Asia. In India, it occurs south of the Brahmaputra River, in the northeastern part of the country. Its range in India extends from Assam and Meghalaya to eastern Arunachal Pradesh, Nagaland, Manipur, Mizoram and Tripura.
It is primarily frugivorous, but eats many types of vegetation, such as seeds, leaves and roots, but also hunts freshwater crabs, frogs, bird eggs and insects.
