Order : PRIMATES
Family : Cercopithecidae
Species : Macaca mulatta

Head-body length : up to 59 cm
Tail length : up to 28 cm
Weight : up to 6 kg

The highly adaptable Rhesus Macaque occurs in lowland forested areas, montane forests (reportedly up to 2500 metres elevation), disturbed secondary habitats, agricultural areas and rural settlements. Large troupes of over
20-30 individuals may be encountered at roadsides, where they have become habituated to begging for food from humans. The maximum troupe size is around 50.

Their body fur is typically pale to medium brown or orange-brown, and their underparts cream. Their hindquarters are often reddish. The tail is  relatively short, being around half the head-body length : this feature distinguishes the Rhesus Macaque from the Long-tailed Macaque whose tail is around 80% of head-body length.

The fur on the crown is swept neatly backwards, and the bare skin on the face is pinkish, becoming reddish in some specimens (particularly females in heat).

The species has been much exploited by man : it is commonly used as a laboratory primate, and has given its name to the Rhesus Factor in blood group systems.

The species is wide-ranging occurring in northern parts of Pakistan, India and Bangladesh, as well as Nepal and southern parts of China.  Within Southeast Asia it is confined to northerly parts of the mainland  including Myanmar, Thailand and northern parts of Indochina.  Hybridization has been documented where the southern part of its range meets the northern part of the range of the Long-tailed Macaque, for example in north Vietnam.

Fig 1 : Sub-adult male with orange-brown fur.

Fig 2 : Sub-adult male with strongly orange-brown fur, and reddish hindquarters.

Fig 3 : A dark brown juvenile breast-feeding.

All photos from West Bengal, northern India.


References :

Francis, C.M. 2019. A Field Guide to the Mammals of South-east Asia. Second Edition. New Holland. 416 pp.

Lekagul, B., McNeely, J., 1977. Mammals of Thailand. Association for the Conservation of Wildlife, Thailand. 758 pp.