Pygathrix cinerea
Creators: name: Russell A. Mittermeier
name: Anthony B. Rylands
name: Don E. Wilson
Publisher: name: Lynx Edicions
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Primates
Cercopithecidae
Pygathrix
Pygathrix cinerea

description: 123.
Gray-shanked Douc
Pygathrix cinerea
French: Douc a pattes grises / German: Grauschenkel-Kleideraffe / Spanish: Duc de patas grises
Other common names: Gray-shanked Douc Langur, Gray-shanked Douc Monkey
Taxonomy. Pygathrix nemaeus cinereus Nadler, 1997,
Vietnam, Gia Lai Province, Play Ku.
Play Ku is a wildlife trade center, and P. cinerea does not occur there naturally. The holotype’s origin is most probably Kon Ka Kinh National Park. There is a small area of sympatry with P. nemaeus in northern Quang Nam Province, Vietnam, and in north-eastern Cambodia (Virachey National Park), with some hybridization. Monotypic.
Distribution. C Vietnam between 16° N and 13° 38" N (Quang Nam, Kon Tum, Quang Ngai, Gia Lai, and Binh Dinh provinces), and a small part in NE Cambodia.
Descriptive notes. Head-body 55-66 cm (males) and 51-568 cm (females), tail 56— 65 cm (males) and 54-62 cm (females); weight 8-12.5 kg (males) and 4.7-11.7 kg (females). Males and females have the same pelage color. Back, nape, and crown of the Gray-shanked Douc have a gray-agouti color that extends to arms, except for insides of forearms. Chest, belly, and throat are very pale whitish-gray. Below its white throat, a broad orange collar is bordered underneath by a black line that joins black parts on shoulders and down to inside upper arms and forearms. Color of legs varies from light gray-agouti to very dark gray-agouti, nearly black, and becoming black on inner side of thighs. Hands and feet are black. Tail is white and has a thin tassel. Above its tail root is a triangular patch of white fur, which in males is further adorned by a pair of tufts at each anterior angle. Facial skin is orange to yellow-brown, except around mouth and chin, where it is white. Eyes are slanted at c.14-5° from horizontal. Long white cheek whiskers frame face to the sides and curve downward, much longer in males than females. Gray-agouti hairs on head have a cape-like form on nape, and a small black frontal band occurs over forehead. Newborn Gray-shanked Doucs have a pale gray-agouti back, a white belly, and very light gray arms. Inner sides of legs are white, and outer sides are light chestnut. From forehead up to the crown, hairs are light chestnut; back of head is gray-agouti. Tail is whitish to grayish-white and has a thin tassel. There is wide variation in facial coloration, from a dark slaty-gray face with more or less extended yellow patches under and over eyes to wider yellow eye-rings with only restricted gray parts around mouth, nose, and forehead. During the first three months of life, young lose the reddish tinge on their heads and legs and change to gray. Tail color changes to white. Slaty-gray parts of face become pale over about the next three years, changing to the yellow-orange facial skin of adults.
Habitat. Evergreen lower and montane moist subtropical forest and mixed broadleaf and needle-leaf moist subtropical forest, even in degraded parts, from elevations of c.200 m up to c.1500 m. Winter and spring are dry and cool, and summer and autumn are humid and warm. Mean annual temperature is ¢.22°C, mean daily maximum temperature in the warmest month is ¢.32°C, mean daily minimum temperature in the coldest month is ¢.11°C, and absolute temperature minimum is ¢.8°C.
Food and Feeding. Gray-shanked Doucs are folivorous but also include fruits and seeds in their diets. Over the year, young leaves are preferred (c.50% of the diet), with mature leaves contributing ¢.10%, ripe fruits 22%, and unripe fruits 10%. There is high seasonal turnover of food items selected. In the dry season, young leaves comprise ¢.80% of the diet, but in the wet season, ¢.18%. The proportion of fruits in the diet changes from less than 10% in the dry season to ¢.35% in the wet season. In all, 166 tree and plant species from 40 families have been identified as providing food for Gray-shanked Doucs. They have a rather high demand for water during digestion, and they use water sources on the ground. About 60% of the water demand is satisfied from their food, and 40% from drinking. Water consumption is correlated with air temperature and increases from 0-10 ml/g body weight at 24°C to 0-16 ml/g body weight at 32°C.
Breeding. Births of Gray-shanked Doucs occur throughout the year, with a peak in January-March. They are sexually receptive every 28-30 days. The gestation period is 165-190 days. A single young is born.
Activity patterns. Gray-shanked Doucs are diurnal and largely arboreal, but also terrestrial, going to the ground to drink water and lick minerals. Their daily activities begin at 05:00-06:00 h and cease at 17:00-18:45 h. Activity budgets change seasonally. In the wet season, they spend, on average, 41% oftheir time resting, 11% feeding, 22% moving, and 26% socializing. In the dry season, c.32% of their time is spent resting, 13% feeding, 31% traveling, and 24% socializing, which also includes interactions among adult males. Activity budgets vary significantly between males and females and age classes. Females spend more time feeding (14%), resting (42%), and moving (20%) than males (11%, 37%, and 17%). Males, on the other hand, spend more time engaged in social activities (35%) than females (24%). Subadults andjuveniles spend less time feeding (c.7%) and more time engaging in social activities (¢.28%) than either adult males or females. Gray-shanked Doucs are largely quadrupedal but frequently brachiate when traveling in the forest canopy.
Movements, Home range and Social organization. Daily travel distance of Grayshanked Doucs is correlated with group size; smaller groups travel less than larger groups. Groups with less than ten individuals travel, on average, less than 500 m/day, with a minimum of 50 m/day for a group of six. Groups with more than 20 individuals travel, on average, more than 2000 m/day, with a maximum of 4000 m/day for a group of 29. Thereis little information on home range size. A large band, consisting of six one-male groups that sometimes traveled together, used a home range of 984 ha. Unimale—multifemale groups in Kon Ka Kinh National Park, Vietnam, averaged 14-8 individuals. Large bands of up to 88 individuals result from up to six groups merging in a fission-fusion system. The most common one-male group had 6-9 individuals (30%), followed by 2-5 individuals (23%) and 10-15 individuals (21%, n = 179). Grayshanked Doucs have four different social units: unimale-multifemale group, all-male groups, multimale-multifemale groups, and single males. The unimale-multifemale group is the most common. A male-to-female sex ratio of c.1:2 (216 individuals in 24 groups) and age class composition of c. 65% adults, 18% subadults, 11% juveniles, and 4% infants have been recorded. Both sexes disperse. The population density in Kon Ka Kinh National Park is estimated at 0-6 ind/km?.
Status and Conservation. CITES Appendix I. Classified as Critically Endangered on The IUCN Red List. Since 2000, the Gray-shanked Douc has been listed as one of the “World’s 25 Most Endangered Primates.” It is protected by law in Vietnam and Cambodia. It was first discovered in 1995 when an individual was confiscated from a restaurant in northern Vietnam. The total population is estimated to be less than 1000 individuals, occurring in a number of isolated populations. The largest population, numbering ¢.200 individuals, lives in Kon Ka Kinh National Park, in Song Thanh, Kon Plong and Kon Cha Rang nature reserves, and in unprotected areas in South Quang Nam Province. They also occur in Mom Ray National Park, Ngoc Linh and A Yun Pa nature reserves, and Ba To Cultural and Historical Site in Vietnam. Gray-shanked Doucs are threatened from habitat loss and poaching, both for food and traditional medicine. They are also susceptible to snaring when on the ground, especially in the more degraded habitats.
Bibliography. Bett (2011), Byron & Covert (2004), Covert et al. (2004), Fooden (1996), Groves (2001), Ha Thang Long (2004, 2009), Ha Thang Long & Nadler (2009), Ha Thang Long et al. (2010), Kullik (2009a, 2009b), Liedigk et al. (2012), Lippold (1998), Lippold & Vu Ngoc Thanh (1995, 1999), Mey (2010), Nadler (1995), Nadler & Streicher (2004), Nadler, Momberg et al. (2003), Nadler, Vu Ngoc Thanh & Streicher (2007), O'Brien (2006), Rawson & Roos (2008), Roos (2004), Roos & Nadler (2001), Roos et al. (2007), Ulibarri (2006).
description: Published as part of Russell A. Mittermeier, Anthony B. Rylands & Don E. Wilson, 2013, Cercopithecidae, pp. 550-755 in Handbook of the Mammals of the World – Volume 3 Primates, Barcelona :Lynx Edicions on pages 725-726, DOI: 10.5281/zenodo.6867065