Douc  (Pygathrix nemaeus)

These colobine monkeys have an extremely striking appearance. At present two subspecies are recognised, the red-shanked douc (Pygathrix nemaeus nemaeus) characteristically has bright maroon legs and reddish patches around the eyes (4). In contrast, the grey-shanked douc (Pygathrix nemaeus cinerea) is less vibrant, with speckled grey legs and orange markings on the face (4). Both have dappled grey bodies, black hands and feet and white cheeks, although the cheek hairs of the red-shanked douc are much longer (4). The black-shanked douc (Pygathrix nigripes) has recently been recognised as a distinct species (1), and it is thought that the little-known P. n. cinerea may also be similarly distinct (2). The long hind limbs and tail allow these monkeys to be wonderfully agile in their treetop habitat (2).

Endemic to Indochina (5), the red-shanked douc is found in central Vietnam and east-central Laos, whilst the grey-shanked douc is known only from the central highlands of Vietnam (4).

Doucs inhabit tropical rain and monsoon forests from sea level to altitudes of 2000 metres above sea level (6).

These monkeys are usually found in groups, ranging in size from four to five individuals to up to 50 (4). These groups may either consist of a single male with females and their young, or have a more multimale-multifemale social system (4). Females become sexually mature at around four years of age (6) and births have been observed to peak during the fruiting season between January and August (4). A single offspring is born after a roughly six-month gestation period (6); young are carried through the treetops on their mothers' front and also by other members of the group (4).

Social bonds within these douc groups are vitally important and communication takes place through a wide variety of vocal and visual signals as well as through tactile communication in the form of social grooming (4). The douc's diet is primarily composed of leaves, concentrating on young tender shoots, although fruit, buds and flowers are also consumed (4). These monkeys are arboreal, spending the majority of their time in the canopy of the forest (4).

Doucs suffer from an extensive level of hunting, for food, live trade and medicinal properties. Despite legal protection, widespread hunting continues (7). Habitat destruction, in the form of logging, is also rife and seriously threatens the future of douc populations (7). The widespread use of defoliants and bombing during the Vietnam War also caused great habitat destruction (6).

Doucs are protected from international trade by their listing on Appendix I of the Convention on International Trade in Endangered Species (CITES) (3), and are also protected by law in Vietnam (7). Populations occur within a number of reserves, such as the Bach Ma National Park and the Kong Cha Rang and Kon Khi Kinh Nature Reserves within Vietnam (4). The Douc Langur Project has been undertaking comprehensive surveys of this species in an effort to understand the distribution of populations, which is vital for any successful conservation programme (7). Their studies are also helping to uncover greater knowledge of this still poorly understood primate, such as group size and composition, and social interactions (7). The World Wildlife Fund's (WWF) Indochina Programme is also carrying out vital research into the effectiveness of national parks within Vietnam (5). The effective enforcement of existing laws and national parks will be the key to ensuring the future of this attractive and appealing primate (7).

For more on the douc see the Primate Info Net:

http://www.primate.wisc.edu/pin/factsheets/pygathrix_nemaeus.html

Authenticated by Matt Richardson, independent primatologist and writer.