Black-shanked douc (Pygathrix nigripes)
|Also known as:||black-shanked douc langur, Black-shanked douc monkey|
|Synonyms:||Pygathrix nemaeus nigripes|
|Size||Head-body length: 55 – 63 cm (2)|
Tail length: 57 – 73 cm (2)
Male weight: 11 kg (2)
Female weight: 8 kg (2)
The black-shanked douc is classified as Endangered (EN) on the IUCN Red List 2007 (1) and is listed on Appendix I of CITES (3). It is listed as Endangered by the U.S. Fish and Wildlife Service (2).
A member of the attractive colobid subfamily, the black-shanked douc has recently gained species status, having previously been a subspecies of the douc langur (Pygathrix nemaeus). Like other doucs, this species is striking, with large, almond-shaped eyes surrounded by yellow circles that stand out against the blue-grey face. White muzzle fur, long, white whiskers, and black forehead fur frame the face, giving the monkey a wise appearance. The black forehead colouration extends over the head and onto the shoulders, where it fades to grey across the back and forelimbs, appearing palest on the belly. The hind limbs are black, and there is a white patch on the rump surrounding the extremely long, tasselled, white tail. Males have a circular white spot on either side of the rump, but are more easily distinguished from females by their blue scrotum and inner thighs, and bright pink penis (2).
This Old World monkey species is found only in eastern Cambodia and southwestern Vietnam (2). Douc is the Vietnamese word for monkey (5).
Inhabits wooded habitats, including both primary and secondary monsoon forests and rainforests, from medium to high altitudes (2) (4).
Active during the day, the black-shanked douc is never seen on the ground in the wild, and spends much of its time feeding high in the forest canopy. Suffering from gastric distress after eating ripe fruit, it prefers unripe fruit and young leaves, which are more easily broken down in its complex four-chambered stomach. The black-shanked douc’s water requirement is provided mostly by its food, but it will also lick the dew from leaves in the morning (2).
Travelling with between 3 and 50 individuals in a group (usually 4 – 25), the black-shanked douc is a very social primate, and individuals will readily play and groom together. Social grooming can last for up to an hour before the afternoon nap, during which pairs sleep together, as do females and their infants. Most groups are multi-male and multi-female, with more females than males, but juvenile males may disperse, forming non-breeding bachelor groups. Motherhood is a shared duty, giving females time to feed, as well as helping to integrate the young into the group. However, females in the group are occasionally aggressive towards one another. Group ranges overlap, and opposing males will threaten each other by brachiating and jumping back and forth whilst slapping their hands against their thighs. Vocalisations are rare, but threats to the group elicit loud calls and barks, and can also cause panic diarrhoea (2).
With no distinct breeding season, the female solicits mating at any time by staring intently at the male with her mouth closed and chin thrust out. Moving her head gently from side to side without lowering her gaze, the female then crouches near the male to mate. Gestation lasts for 180 to 190 days, during which time the female is not socially active, preferring to keep calm and quiet. She will continue to care for the group’s young, however, until two weeks before the birth of her own infant. Females wait between a year and three years before giving birth again. Black-shanked doucs can live for up to 30 years (2).
Vietnam has been subject to rapid human population growth, and has now lost 80 percent of its historical forest cover. The Vietnamese government has a policy of relocating landless northerners to the central highlands, thereby subjecting the remaining forests to clearance and commercial logging. In addition, the black-shanked douc is hunted for meat and for trade in the traditional Chinese ‘medicine’ industry. Populations of doucs are increasingly fragmented, reducing the opportunity for gene flow, which prevents inbreeding depression (2).
Whilst the black-shanked douc occurs in many wildlife reserves and national parks, and is protected by at least 11 national laws, law enforcement is weak and reserves are poorly guarded. This species is difficult to keep in captivity, but captive breeding programs at San Diego and Cologne Zoo have been successful (2).
For further information on the black-shanked douc see:
The San Diego Zoo Zoological Society Library website:
Authenticated (12/03/05) by Matt Richardson.
- Brachiation: in some primates, a method of locomotion when the animal swings hand over hand from branch to branch.
- Gestation: the state of being pregnant; the period from conception to birth.
- Inbreeding depression: the reduction in viability, birth weight, and fertility that occurs in a population after one or more generations of inbreeding (interbreeding amongst close relatives).
- Primary forest: forest that has remained undisturbed for a long time and has reached a mature condition.
- Secondary forest: regenerating forest that has not yet reached the mature state of primary forest.
- 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.
IUCN Red List (March, 2008)
San Diego Zoo Zoological Society Library (January, 2005)
CITES (January, 2005)
- Richardson, M. (2005) Pers. comm.
The Douc Langur Project (March, 2008)