Assam macaque (Macaca assamensis)
|Also known as:||Assamese macaque, hill monkey, Himalayan macaque|
|Synonyms:||Macaca coolidgei, Macaca macclellandii, Macaca problematicus, Macaca rhesosimilis, Macaca sikimensis|
|French:||Macaque D' Assam|
|Spanish:||Macaca Del Himalaya|
|Size||Head-body length: 51 - 73.5 cm (2)|
Tail length: 15 - 30 cm (2)
Male weight: 6 - 12 kg (3)
Female weight: c. 5 kg (3)
- The Assam macaque is a fairly thick-set monkey with a relatively short tail.
- Two subspecies of Assam macaque are currently recognised, but a separate population in Nepal may potentially be a third.
- The Assam macaque generally inhabits forests in upland areas.
- A social species, the Assam macaque lives in small groups which include males, females and juveniles.
The Assam macaque is classified as Near Threatened (NT) on the IUCN Red List (1) and is listed on Appendix II of CITES (4). The eastern Assamese macaque (Macaca assamensis assamensis) and the western Assamese macaque (Macaca assamensis pelops) are both listed as Near Threatened (NT) on the IUCN Red List (1).
A species of Old World monkey, the Assam macaque (Macaca assamensis) is a rather thick-set macaque with a relatively short, well-haired tail (2). However, the length of the tail of this species can vary, with some individuals possessing shorter tails which do not reach to the knee, and others having much longer tails (5).
The fur colour of the Assam macaque ranges from a deep reddish-brown or dark brown to a lighter yellow-brown, with the front part of the body tending to be paler than the rear part (2) (5). The underparts of the body are a paler, more whitish colour, and the bare skin on the face varies between dark brown and purplish (2) (5), with paler pinkish to whitish-yellow skin around the eyes (5). The Assam macaque’s whiskers and beard are fairly well developed (5), and it also has cheek pouches that are used to store food when foraging (3).
As in most macaques, the male Assam macaque is larger than the female. Juvenile Assam macaques vary in colouration, but are generally paler than the adults (5).
A number of vocalisations have been recorded in the Assam macaque, including a ‘thruuu’ alarm call when a human is spotted (5) and a ‘pio’ sound generated when a deer is seen (2) (5).
The Assam macaque inhabits the foothills of the Himalayas and the neighbouring mountain ranges of Southeast Asia, with its distribution extending from Nepal and northern India, through southern China, Bhutan and Bangladesh, to Myanmar, Lao People’s Democratic Republic, northern Thailand and northern Vietnam (1) (2) (3).
Two distinct subspecies are currently recognised: the western Assamese macaque (M. a. pelops), which occurs in Nepal, Bangladesh, Bhutan and India, and the eastern Assamese macaque (M. a. assamensis), which occurs from Bhutan, India and China to Vietnam. A separate population of the Assam macaque, found only in Nepal, may potentially represent a further subspecies (1).
The Assam macaque inhabits various forest habitats, including tropical and subtropical evergreen forest, dry deciduous forest and montane forest (1) (3). Although particular habitats and niches vary among the subspecies, the Assam macaque can be found from floodplains up to high mountains, reaching elevations of up to 2,800 metres or sometimes even 3,000 metres. Most commonly, the Assam macaque is an upland species which is found in hill areas above elevations of 1,000 metres (1).
Sleeping sites chosen by this species are known to include rocky cliffs along steep banks of rivers and streams, as this can provide the Assam macaque with protection against predators (5).
Like most macaques, the Assam macaque is active during the day, and walks around on all fours. It travels mostly on the ground, but will also feed in trees and bushes. Much of this macaque’s time is spent resting or grooming, which usually takes place on the ground or on rocky terrain (3).
Leaves, fruits and flowers form a large part of the Assam macaque’s diet, although it is thought that insects and small vertebrates, including lizards, may also be consumed (2) (3) (5). This species is highly social (6) and generally lives in small groups of around 10 to 15 individuals (3), which include males, females and juveniles (5). However, groups of up to 50 individuals have also been observed (5). Assam macaque groups have strict dominance hierarchies (7). Female Assam macaques remain in the group into which they were born, whereas males disperse from the group once they reach maturity (8).
The breeding season of the Assam macaque has been recorded as November to December in Nepal (5) and October to February in Thailand (8). The skin on the female’s posterior becomes red when she is ready to mate (3), and during this time the female will present herself to passing males (5). The gestation period of the Assam macaque is around 158 to 170 days (8), and the female gives birth to a single offspring which weighs around 400 grams at birth (6).
Female Assam macaques usually give birth for the first time at around five years old, and are likely to have an infant every one to two years (3) (8). The lifespan of the Assam macaque is unknown (6).
The primary cause of the decline in the Assam macaque is habitat loss (1), with forests being cleared for agriculture and logging, as well as for the creation of roads and for firewood (9). Other threats to this species include hunting and trapping for sport, food, the pet trade and traditional medicine, and it may also be impacted upon by invasive non-native species (1).
Hunting for its skin to make footwear, and for its bones to make glue or balm, is also a contributing factor to the Assam macaque’s decline. In India, the skulls of this monkey are used as an ‘evil eye’ in front of locals’ houses (1). The Assam macaque is also considered to be a crop-raiding pest, and conflicts occur between this species and local people in some areas (9).
The Assam macaque is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that any international trade in this primate should be carefully controlled (4). In all of the countries where this species occurs, legal protection is in place. For many countries, including India, Thailand and Bangladesh, the Assam macaque is listed under Wildlife Protection Acts (1).
The Assam macaque has been found in at least 41 protected areas in north-eastern India and is also present in a number of National Parks (1). To help protect this species and its habitat, education programmes have taken place in some Himalayan National Parks to try and encourage locals to use an alternative energy source rather than firewood. Measures to reduce conflict between the Assam macaque and local people have also been suggested (9).
Find out more about the Assam macaque:
BBC Science & Nature: Wildfacts - Assamese macaque:
More information on primate conservation:
IUCN/SSC Primate Specialist Group:
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
- Deciduous forest: forest consisting mainly of deciduous trees, which shed their leaves at the end of the growing season.
- Evergreen forest: forest consisting mainly of evergreen trees, which retain leaves all year round. This is in contrast to deciduous trees, which completely lose their leaves for part of the year.
- Gestation: the state of being pregnant; the period from conception to birth.
- Montane forest: forest occurring in mountains.
- Subspecies: a population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.
- Vertebrates: animals with a backbone, including mammals, birds, reptiles, amphibians and fish.
IUCN Red List (December, 2011)
- Francis, C.M. (2008) A Field Guide to the Mammals of South-East Asia. New Holland Publishers, London.
- Smith, A.T. and Xie, Y. (2008) A Guide to the Mammals of China. Princeton University Press, New Jersey.
CITES (December, 2011)
- Chalise, M.K. (2003) Assamese macaques (Macaca assamensis) in Nepal. Primate Conservation, 19: 99-107.
BBC Science & Nature: Wildfacts - Assamese macaque (December, 2011)
- Cooper, M.A. and Bernstein, I.S. (2008) Evaluating dominance styles in Assamese and rhesus macaques. International Journal of Primatology, 29: 225-243.
- Fürtbauer, I., Schülke, O., Heistermann, M. and Ostner, J. (2010) Reproductive and life history parameters of wild female Macaca assamensis. International Journal of Primatology, 31: 501-517.
Regmi, G.R. and Kandel, K. (2008) Population Status, Threats and Conservation Measures of Assamese Macaque (Macaca assamensis) in Langtang National Park, Nepal. Final Report submitted to Primate Society of Great Britain, UK. Available at: