Lee Kong Chian Natural History Museum

Macaca fascicularis (Raffles, 1821)

Species:M. fascicularis
Common Names:Long-tailed Macaque, Crab-eating Macaque


The Long-tailed Macaque measures up to 45 cm (head and body) and can be identified by its long tail (56 cm). It also has long limbs. The fur is generally greyish brown, olive brown or reddish brown, with the colours being paler ventrally. The face is brownish-grey with prominent cheek whiskers.

Read more about the Primates order.
Read more about the Cercopithecidae family.


The species ranges from Indochina, Southern Thailand, Peninsular Malaysia, Singapore to Sumatra, Java, Borneo, and the Philippines.


In Singapore, it can be found in several places including Admiralty Park, Bukit Batok Nature Park, Bukit Timah Nature Reserve, Central Catchment Nature Reserve, Lim Chu Kang, Pasir Ris, Pulau Hantu, Pulau Tekong, Pulau Ubin, Sentosa, Sisters Island, Southern Ridges, Sungei Buloh Wetland Reserve and Western Catchment.

Locality Map

General Biology

The Long-tailed Macaque is fairly common and frequently encountered along forest edges, mangroves, plantations, and cultivated lands. They spend a large amount of time active in the low trees and thick scrub.

It lives in social groups of up to about 30 individuals, led by as many as four adult males and up to 12 adult females, with the rest being immature. A strict social hierarchy is maintained within the group. Males join and leave groups throughout their lifetime, and the most dominant male in each group has the greatest access to mates.

In some parts of Singapore, monkeys have associated humans with food provisioning, leading to human-monkey conflicts.


It forages in the day for fruit and small animals such as insects and crabs, and hence, is also known as the Crab-eating Macaque.

Life Cycle

Males reach sexual maturity at approximately six years of age, whereas females mature by about four years of age. Females can produce young each year if it is high ranking, and every other year otherwise. The gestation period averages approximately 162 days. It is known that the births in this species peak from May to July, corresponding with the rainy season. Females provide the bulk of the care for offspring and young are nursed until they are approximately 420 days of age. Young females are likely to remain in the troop into which they were born, whereas males are likely to emigrate at or near sexual maturity.

Other Resources

Ecology Asia. 2013. Long-tailed Macaque. http://www.ecologyasia.com/verts/mammals/long-tailed_macaque.htm. (Accessed January 2013).


Baker, N. and K. K. P. Lim. 2008. Wild Animals of Singapore: A Photographic Guide to Mammals, Reptiles, Amphibians and Freshwater Fishes. Vertebrate Study Group, Nature Society (Singapore). 180 pp.

Chua, M.A.H. & K.K.P. Lim, 2011. Macaques. Pp. 370. In: Ng, P. K. L., R. T. Corlett & H. T. W. Tan (editors), Singapore Biodiversity. An Encyclopedia of the Natural Environment and Sustainable Development. Editions Didier Millet, Singapore, 552 pp.

Francis, C. M. 2008. A Guide to Mammals of Southeast Asia. New Holland Publishers (UK) Ltd, United Kingdom, 392 pp.

Kavanagh, M. and E. Laursen, 1984.  Breeding seasonality among long-tailed macaques,Macaca fascicularis, in Peninsular Malaysia. International Journal of Primatology, 5(1): 17-29.

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