Order : PRIMATES
Family : Cercopithecidae
Species : Rhinopithecus avunculus

Head-body length : 51-62 cm
Tail length : 66-92 cm
Weight : males 14 kg, females 8.5 kg

The Tonkin Snub-nosed Monkey, or Dollman's Snub-nosed Monkey, is one of just two species of the genus Rhinopithecus occurring in Southeast Asia, the other being the Myanmar Snub-nosed Monkey (Rhinopithecus strykeri). There are three other species of the genus in China.

This is one of the rarest and most endangered primates in the world, with a population estimate of less than 250 individuals, and numbers may still be declining due to habitat loss and hunting. They are highly vulnerable to being shot by poachers as they are reportedly not shy of humans.

The species inhabits primary, evergreen forest in areas of karst limestone up to 1200 metres elevation. It is largely arboreal, only rarely coming to ground. It feeds on young leaves, forest fruits and seeds.

Its fur colour and patterning is unmistakable, being immaculate white on the face, chest and inside the arms and legs, and black elsewhere. It has pronounced eye-rings tinged with blue, and orange fur beneath the chin (which may be more pronounced in males). Its tail is long and is typically dark on top and pale beneath. Infants are grey and white, and lack an orange throat patch.

Its facial features are also unmistakable - its lips are thick and bright pink, and the nose is flat and upturned. The ears are tufted.

Males weigh up to 14 kg, and females are considerably smaller at 8.5 kg.

The species only occurs in Vietnam, and is confined to a few fragmented forests in the northern provinces of that country. IUCN (Quyet et al, 2020) list the species as occurring in two protected areas in Vietnam - the Na Hang and Cham Chu nature reserves.

Fig 1 : An adult male takes a curious look at the photographer while resting high on a branch.

Fig 2 : The male is accompanied by a female, which is around 40% smaller than the male.

Fig 3 : The male surveys his surroundings, thereby revealing the bright orange fur beneath the throat.

All photos extracted from a video filmed by Andie Ang in Ha Giang Province, Vietnam. The monkeys were sighted late morning, at an elevation of 880 metres.


References :

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

Quyet, L.K., Rawson, B.M., Duc, H., Nadler, T., Covert, H. & Ang, A. 2020. Rhinopithecus avunculus. The IUCN Red List of Threatened Species 2020: e.T19594A17944213.