The decline in douc langurs is due primarily to hunting by humans. They are hunted both for food and for sport. The forest habitat occupied by this species also experienced intense disruption during the Vietnam war. In areas of Vietnam where defoliants were used during the war, reproduction of P. nemaeus has suffered. (Lippold, 1995; Wisconsin, 2002)
Known Predators:
Douc langurs ares also known as "costumed apes" for their magnificent colors. Although all members of the species have gray bodies, white tails, and big pot-bellies, the three subspecies can be distinguished by their different color patterns.
Red-shanked douc langurs (P. nemaeus nemaeus) have black hind legs with maroon "leg warmers" from knee to ankle. The forearms are white from the elbow to the wrist. The body is gray with tri-colored agouti hairs (marked with black, white and gray). The genitals of males of this subspecies are striking, because of the white scrotum and a penis which is bright red when erect. The perineum is white, and males have patches of white on each side of their white rump patch. These white rump patches are absent on females, allowing easy differentiation of the sexes. The faces of these langurs are also conspicuously marked, with long, white hairs on the cheeks, and reddish-yellow fur on the rest of the face. There are two bands of color over the eyes, one red above one black. (Wisconsin, 2002)
Black-shanked douc langurs (P. nemaeus nigripes) have all black hind legs and gray forearms. The gray fur on the chest is lighter than it is elsewhere on the body. The area of the face is colored black, and the white hairs on the cheeks are short. Above the eyes, the two bands of color are reversed from those found in P. nemaeus nemaeus, with the black being found over the red. The perineum of this subspecies is white, and males have characteristic white rump patches, but the scrotum of males is blue. (Wisconsin, 2002)
The remaining subspecies, P. nemaeus cinerea, has mainly gray agouti fur, although the shoulders are black, and the chest, neck, tail, perineum, face, lips, and cheeks are white. The hind feet are colored black, and the forefeet, or hands, are gray with black fingers. The facial skin is goldish-brown, and there are orange markings on the nose and in between the eyes. There is also a band of orange-black color that on the neck that blends into the black on the shoulders. The band of color above the eyes is black. (Wisconsin, 2002)
The young are slightly lighter in color until they reach about 10 months of age. (Kavanagh, 1987)
Adult males weigh an average of 10.9 kg, and the smaller females average about 8.2 kg (Wisconsin, 2002). The average head and body length is 610 to 762 mm, with the tail adding an additional 558 to 762 mm (Nowak, 1999).
Pygathrix nemaeus has a sacculated stomach, which assists them in breaking down plant cellulose and obtaining nutrition from it. The dental formula is 2:1:2:3. (Wisconsin, 2002)
Average mass: females, 8.2 kg; males, 10.9 kg.
Range length: 610 to 762 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry ; polymorphic
Sexual Dimorphism: male larger
Average mass: 9720 g.
Lifespan is 24 years or more in captivity. (Lippold, 1989)
Range lifespan
Status: captivity: 24+ (high) years.
Average lifespan
Sex: male
Status: captivity: 25.0 years.
Average lifespan
Sex: male
Status: captivity: 21.0 years.
Douc langurs are mostly found in tropical rainforest and monsoon forest (both primary and secondary forest). (Lippold, 1977)
Range elevation: 0 to 2000 m.
Habitat Regions: tropical
Terrestrial Biomes: rainforest
Red-shanked douc langurs (Pygathrix namaeus nameaus) are found innorth and central Vietnam, east-central Cambodia and possibly in China (on the island Hainan). Another subspecies, black-shanked douc langurs (P. nemaeus nigripes) are found in southern Vietnam, southern Laos and eastern Cambodia. The subspecies P. nemaeus cinerea occurs in the central highlands of Vietnam. (Lippold, 2001a; Wisconsin Primate Research Center, 2002)
Biogeographic Regions: oriental (Native )
In recent years it has been found that douc langurs are actually more closesly related to proboscis monkeys and snub-nosed monkeys than to other langurs. The word "douc" (pronounced "dook") is an ancient name of Vietnamese origin. (Oates, 1994)
Douc langurs are highly social and therefore have a great repetoire of communication patterns, sharing visual, tactile, and accoustic information.
Like many other primates, doucs have a specific "play face" that they display with their mouth open and their teeth partially showing. A grimace with their teeth showing is used to initiate grooming or play. A stare, with raised-eyebrows is used as a threat, and is often responded to with a submissive grimmace. A jaw-thrusting/head shaking face is used to initiate sexual interactions, and presenting is used when a female wishes to engage in copulation.
A low-pitched growl is made to threaten other members of the group. Loud barks and quickly moving around the trees while hitting branches with both their hands and feet can be a sign of threat. (Oates, 1994) This call can also occur during feeding (Wisconsin, 2002). A squeal is often heard during agonistic encounters. A faint, bird-like call, called a twitter, is often used in response to a stare or before social grooming, and is thought to be a submissive signal, allowing another animal to approach without fear of an aggressive response (Wisconsin, 2002).
The main tactile communication channels are social grooming and play. In social grooming, parasites, dandruff flakes and other junk is removed from another monkey's fur with the hands and mouth. Females are the most active groomers, grooming each other, infants and juveniles, and adult males. Grooming is thought to reinforce social bonds between individuals. During play, these monkeys may wrestle, hit, chase, touch, pull on, and mouth one another. (Wisconsin, 2002).
Communication Channels: visual ; tactile ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Douc langurs have become endangered due to deforestation, hunting, and the illegal pet trade. They have also been captured and removed from the wild for use in medical research. (Lippold, 1995)
US Federal List: endangered
CITES: appendix i
IUCN Red List of Threatened Species: endangered
Pygathris namaeus is not known to have nay negative effects on humans.
Some langurs are collected for the pet trade, and some are hunted for food.
Positive Impacts: pet trade ; food
This monkey is primarily herbivorous. It also eats seeds, and therefore probably contributes to plant dispersal. (Pham, 1993)
Ecosystem Impact: disperses seeds
Douc langurs eat mainly leaves, which comprise about 82% of their diet. Although they prefer young, tender leaves, which are more easily digested than older, tough leaves, the digestion of these leaves is still mainly accomplished by their sacculated stomach, which helps them to break down cellulose. They also consume unripe fruits and their seeds (comprising 14% of their diet), and flowers (4% of the diet). Interestingly, douc langurs don't drink water, instead obtaining the moisture they need from the other foods they eat. (Wisconsin, 2002)
Doucs are very particular when foraging for food. Leaves and fruits are picked and eaten only after close inspection. If leaves are old or fruit is either ripe or overripe it is then discarded. (Pham, 1993)
Plants eaten include: Garcilinia multiflora leaves, Garcilinia oblongifolia leaves, Garcilinia cowa leaves, Garcilinia mangostana leaves, Ficus vasculosa leaves, Ficus chrysocarpa leaves, Ficus retusa leaves, Ficus variegata leaves, Ficus glomerata leaves, Teonogia tonkinensis leaves, Bischofia trifoliata leaves, Phyllanthus emblica leaves, Bacaurea sapida leaves, Dracontomelum duperreanum leaves, Allospondias lakonensis leaves, Choerospondias axillaris leaves, Canarium tonkinense leaves, Canarium album leaves, Canarium nigrum leaves, Andenathera microsperma leaves, Polyalthia nemosalic leaves, Chisocheton paniculatus leaves, Anamixis grandifolia leaves, Averrhoa carambola leaves, Clausenia lancium leaves, Musa coccinea leaves, Castanea mollissma fruits, Castanopsis boisii fruits, Paasania ducampi fruits, Quercus platycalyx fruits, Madhuca pasquieri fruits, Eberhardtia tonkinensis fruits, Ficus vasculosa fruits, Ficus chrysocarpa fruits, Ficus hispida fruits, Ficus retusa fruits, Ficus variegata fruits, Ficus religiosa fruits, Ficus glomerata fruits, Tenongia tonkinensis fruits, Broussonetia papyrifera fruits, Endosperma chinese fruits, Bischofia trifoliata fruits, Phyllanthus emblica fruits, Bacaurea sapida fruits, Dracontomelum duperreanum fruits, Allospondias lakonenis fruits, Choerospondias axillaris fruits, Dubanga sonneratiodes fruits, Canarium tonkinense fruits, Canarium album fruits, Canarium nigrum fruits, Nephellium bassacense fruits, Nephellium chryseum fruits, Euphoea longana fruits, Eugenia brachiata fruits, Peltoforum tonkinense fruits, Polyalthia nemosalic fruits, Chisocheton paniculatis fruits, Averrhoa carambola fruits, Dillenia heterocephala fruits, Clausenia lancium fruits, Caryota urens fruits, Gnetum montarum fruits, Musa coccinea fruits, Grewia paniculata fruits, Peltoforum tonkinense flowers, Adenantheria microsperma flowers, Averrhoa carabola flowers, Garcilinia oblongifolia shoots, Bambusa spinosa shoots, Dendrocalmuys pattelaris shoots, Neohouzeaua dullosa shoots, Garcilinia multiflora buds, Garcilinia oblongifolia buds, Garcilinia cowa buds, Ficus hispa buds, unripe fruits, seeds and flowers.
Plant Foods: leaves; seeds, grains, and nuts; fruit; flowers
Primary Diet: herbivore (Folivore )
Right before mating, both the male and female give each other sexual signals. Males and females both conduct the following display, directed at members of the opposite sex: They drop their jaw forward, lift their eyebrows up then down, then shake their head. The female makes the first move, and has always been observed to initiate the copulation. She lies down on a branch and eyes her chosen mate by looking over her shoulder, a position called "presenting." The male will give a stare back then aproach the female and give a signal if he would like to move some place else to mate or stay where she has chosen. Not all times that a female presents to the male are followed by copulation. Both single and multiple matings have been reported.
(Lippold, 1989; Wisconsin, 2002)
Mating System: polygynous
Female menstrual cycles have an apprximate duration of 28 to 30 days. During estrous, the perineum of the female becomes swollen and red.
After impreganation, gestation lasts an estimated 165 to 190 days. The perineum remains swollen and red. In the wild, births peak between February and June when the fruit is plentiful. The female gives birth to one young and twins are rare. During birth, females often touch their vagina, and move between squatting and stretching positions. Females help the baby to emerge by pulling on it. The infant, in turn, helps to deliver itself by pulling on the mother's fur once its arms are free. After birth, the infant is licked clean, but in captivity, there has been no observed consumption of the afterbirth.
There is no information available on the duration of nursing. Captive females have an interbirth interval around 2 years.
Sexual maturity for females is at the age of 4 years and for males about 4 to 5 years.
(Lippold, 1989; Nowak, 1999; Wisconsin, 2002)
Breeding interval: The interbirth interval of these monkeys has not been reported.
Breeding season: Breeding occurs from August to December, with births following between February and June.
Range number of offspring: 1 to 2.
Range gestation period: 165 to 190 days.
Range age at sexual or reproductive maturity (female): 4 to 5 years.
Range age at sexual or reproductive maturity (male): 4 to 5 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average birth mass: 393.5 g.
Average number of offspring: 1.
The baby clings to its mother from the minute it is born. Infants are typically carried on the mother's belly. Females nurse their infant from both nipples. An orphaned infant was observed being fed by two females in the group and also cared for by a male.
(Lippold, 1989; Wisconsin, 2002)
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Male, Female); pre-independence (Provisioning: Female, Protecting: Male, Female); extended period of juvenile learning
The red-shanked douc (Pygathrix nemaeus) is an arboreal and diurnal Old World monkey belonging to the Colobinae subfamily. They are endemic to Laos, Vietnam and Cambodia. They are known for their bright colors and express exhibit sexual dimorphism through their body size. The species have been declared critically endangered by the International Union for Conservation of Nature, with the main threats being from hunting, habitat loss and pet trade. They are one of three species in the genus Pygathrix, the other two being the black-shanked (P. nigripes) and gray-shanked (P. cinerea) doucs.
Red-shanked doucs live in fission-fusion, multilevel societies that have a mean of 18 individuals per band. They are folivorous and consume mainly Acacia pruinescens, Ficus racemosa, Millettia nigrescens, Zanthoxylum avicennae and Castanopsis ceratacantha. Their four-chambered stomachs that allow for bacterial fermentation help them with their high-fiber diet.[4]
The red-shanked douc is native to Indochina; Vietnam, southern Laos and possibly northeastern Cambodia, east of the Mekong river.[5] Before 1967, the douc was completely unstudied. It is the only douc species that inhabits all three countries of Indochina.[6] In Laos, red-shanked doucs occur from the southern Nam Ghong Provincial Protected Area to the central-north part of the country.[5] Laos is believed to have the largest population of red-shanked doucs, with Nakai-Nam Theun National Protected Area in central Laos having the most individuals of approximately 4,420 groups, followed by the Hin Namno National Protected Area.[7] In Vietnam, the species lives between Nghe An and Gia Lai provinces, from 18°29'N to 14°21'N.[6][8] The Son Tra Nature Reserve in central Vietnam holds the greatest Vietnamese population with approximately 700–1300 individuals.[9] The Phong Nha – Kẻ Bàng National Park is also an important Vietnamese site for the species.[6]
There was one observation of the red-shanked doucs in Cambodia by Rawson and Ross in 2008 in the Ratanakiri Province at the border of Vietnam.[10] There was a report of a red-shanked douc specimen that was given to the Staatliches Museum by the Dresden Zoological Garden who had said that it originated in Hainan, China but the zoo records no longer exist so it remains uncertain.[11]
Red-shanked doucs are found in evergreen, semi-evergreen and occasionally limestone forests, up to 1,600 metres (5,200 ft) in elevation.[6] They are arboreal and spend most of their time in the forest canopy, including to sleep.[10] They occasionally get on the ground to drink water or eat dirt that contains minerals. According to an ecological niche model, red-shanked doucs can live between approximately 14°N to 21°N.[12] Their home range is approximately 36 hectares (89 acres) and they have a core area of 8 hectares (20 acres), with a smaller range in the dry season of 24 hectares (59 acres) and a larger range in the wet season of 33 hectares (82 acres).[13] There are weak correlations between precipitation, temperature, and diet and home range but not enough to draw conclusions from them.[13]
Like other doucs, the red-shanked douc is a long, slender monkey. The male has a head and body length of 55–82 centimetres (22–32 in) with a tail that measures 56–74 centimetres (22–29 in), and the female is between 60–63 centimetres (24–25 in) long with a tail that measures 44–60 centimetres (17–24 in) long. Males weigh 8.6–11.4 kilograms (19–25 lb), and females 6.6–10.5 kilograms (15–23 lb).[13]
The red-shanked douc are among the most colorful primates. They are considered "Queen of primates" thanks to their distinctive and unique appearance. They have agouti hair on their crown, temples, inner thighs, ventral coat, nape of the neck, back, triceps and lateral sides of their arms. Their crown is silver, their temples are red hair and their foreheads are black. They have white whiskers that are approximately 12 cm long for adult males. Their eyes have a high axis. The fur on their cheeks and on their throat is white. Their collar is orange with black from one shoulder to the other. Their face is a yellow-brown color and they have light blue eyelids. Their inner arms and inner, lateral and back thighs are black while their lower legs are a vibrant red. Their abdomen and back are silver yet their sacral area is white. Both feet and hands are black as well as their nipples. Their tails are white and are oftentimes equal in length to their head and body length.[13]
The coloration gradually becomes less vibrant and having smaller red patches with more southern latitudes.[5] In Nam Ghong Provincial Protected Area in Laos, red-shanked doucs only have small red patches around their ankles.[13]
Although minor, the red-shanked doucs are sexually dimorphic with respect to body size but not coloration.[13] There is a slight difference in rump markings between males and females; the male has round white spots above the triangle of white on his rump, while the female does not.[14] Males of all ages have a white spot on both sides of the corners of the rump patch, and red and white genitals.
This monkey communicates using facial expressions. It has a specific "play face" with the mouth open, teeth partially bared and chin thrust forward. Sometimes, it closes its eyes and paws blindly towards another douc without regard for the hazards of doing so when up a tree. A fixed stare is a threat display. A grimace with the mouth open and the teeth exposed is a submissive gesture given in response to a stare and is also used to initiate grooming or play. The red-shanked douc has a low-pitched growl that is given as a threat, and a short, harsh distress squeal. During adult play, they perform an eyelid display where they blink their eyes open and closed to show their light blue eyelids.[15]
They are a fairly peaceful species and agonistic behavior has been very rarely reported. In the San Diego Zoo, researchers observed that in the instances where there was agonistic behavior, it only lasted a few seconds and did not result in injury.[15] Grooming lasts up to an hour and is most commonly found between adult females. In captivity, young red-shanked doucs groom and care for infants, showing signs of alloparental care.[13]
The activity budget of wild red-shanked doucs is rest at 35.3%, movement at 28.6%, socializing at 21.7%, feeding at 13.7% and self-grooming at 0.7%.[16]
Red-shanked doucs live in multilevel, fission-fusion societies in one-male/multi-female or multi-male/multi-female groups with a male-to-female ratio of 1.0:1.63 and an adult-to-young ratio of 1.1:1.0. The bands contain a mean of 18 individuals in a mean of 2.7 units per band and a mean of 6.5 individuals per unit.[16] Groups of up to 50 have been recorded. Group size changes according to the season.[17] Both males and females have their own hierarchies and males are dominant to females. Both males and females will eventually leave the group they were born into.
Red-shanked doucs fuse overnight and fission during mornings and early afternoons.[16] When they are fused, they rest more and when they fission, they are more active.[13]
There does not seem to be any difference in daily fission-fusion from wet to dry season yet overall fission-fusion events increase during part of the wet season, from October to December. In a study at the Son Tra Nature Reserve, 55.32% of their observations were fusion events and 44.68% were fission events. This behavior is believed to help with regulating feeding competition. Red-shanked doucs are very inflexible with membership into their groups.[16]
In captivity, red-shanked doucs use brachiation for almost half of their locomotion whereas, in the wild, arm-swinging accounts for an average of 18% of locomotion. Juveniles use arm-swinging the most (34.3%), followed by subadults (21.7%), adult females (17.6%), adult females carrying infants (15.5%), and then adult males (9.8%). This showed that with increased body weight there is a decreased amount of brachiation.[18]
When they travel by foot, their tail will usually hang down.[19] Like all other Old World monkeys, its tail is not prehensile. It uses its tail solely for balance, and it uses its arms and legs to move through the forest along established routes. When on the move, the group is led by adult males, with juvenile males bringing up the rear and the females and infants staying safe in the middle. This douc is an aerial specialist, moving high up in the canopy. It is very agile and frequently makes breath-taking leaps of up to 6 meters (20 feet), leaping with its arms outstretched over its head, pushing off with its legs and landing on two feet.
When the group is untroubled, the red-shanked douc will move noisily from branch to branch through the forest, crashing through foliage, swinging under branches and leaping with two feet together, displaying its remarkable sense of balance. But when a group is disturbed, by either a predator or other dangers, it can flee silently through the trees, away from danger. If it is startled, it may produce loud barks and rush around the trees slapping branches with its hands and feet.
In captivity, female red-shanked doucs reach sexual maturity at four years old and males at four years and eight months.[10] Mating occurs all year but has peaks between August-December.[10] Mating is initiated by both genders jutting their jaw forward, raising and lowering their eyebrows, shaking their head and squinting their eyes.[15] Copulation occurs after the female crouches and presents her sex organ to the male.[15] Single-mount and multiple-mount matings have been reported. Copulation can still happen while the female is pregnant. Female red-shanked doucs go into estrus every 28-30 days and with it, there is a reddening of their rump.[13]
Female doucs have an average menstrual cycle of 26.4 days, with their follicular phase lasting an average of 13.1 days and their luteal phase lasting 14.8 days. Estradiol and estrone are the main types of estrogen present in female red-shanked doucs.[20]
Births occur year-round but peak between August and October and again between February and April.[13] The birth interval is between 16-38 months.[21] The gestation period lasts between 165 and 210 days, resulting in the birth of a single offspring or very rarely, twins.[10][13] In captivity, it was observed that the pregnant female will find a high place in the enclosure to give birth.[13] The head of the infant emerges after 90 minutes of labour which is followed by the placenta that weighs 90-120g.[21] The oldest recorded birth was from a 26 year old female.[13]
The young are born with their eyes open and they latch on to their mothers instinctively. The baby's body coloration is lighter than an adult's. Its face is more of a blue color and the body is a lighter beige.[13] As it grows older, its body darkens while its face lightens, achieving adult colors at 10 months.[13] In captivity, other group members may look after an infant, and other females may even suckle it. In one study, an orphaned infant was fed by two females in the group and also cared for by a male. The first six months of a red-shanked douc's life is the most challenging. In captivity, they can live for up to 25 years.[10]
Red-shanked doucs are highly folivorous. In the Son Tra Nature Reserve found they consume 54.8% buds and young leaves, 22.6% mature leaves, 3.7% leaf petioles and 18.9% other plant parts. Per month, they found that the red-shanked doucs consumed a mean of 18 species per month and a total of 226 species consumed altogether. Out of the 226 species, there are five species that were eaten 47-82% of the time: Acacia pruinescens, Ficus racemosa, Millettia nigrescens, Zanthoxylum avicennae and Castanopsis ceratacantha. Red-shanked doucs are selective feeders and flexible eaters because of their ability to eat a wide variety of food in all seasons. Fruit is consumed mainly in the morning, which is common amongst leaf-eating monkeys as this is where they derive their energy for the day.
They have different eating patterns during the wet season and the dry season both in what they eat and in the parts of the plants that they eat, although it is not a drastic change. Figs however, are consumed all year long and make up 16-36% of their diet. It is the second most commonly consumed plant by the monkeys and they eat the fruit, leaves and flowers.[17]
They eat peacefully together, not quarreling over food, and have been known to share their food with others. Often, they will share the same clump of foliage and may even break pieces off and hand them to each other, a type of active generosity that is rare among Old World monkeys.[22] Like all other doucs, they do not have cheek pouches.[23]
In 2000, the IUCN Red List of Threatened Species classified the red-shanked douc langur as endangered.[20] In 2020, the IUCN updated their classification of the species to critically endangered due to the population’s continual decline. It was also listed in the Vietnam Red Book in 2007. In 2019, the Vietnamese Prime Minister classified them as a high risk species that needs protection in Decree 06.[9] The species is listed in CITES I which prohibits commercial international trade.[3] More than half of the species has been lost in the past 30-40 years.
The main threat for the red-shanked douc is from hunting. The meat is used for food, traditional medicine and for international sale or trade.[7] Local people often hunt the species for consumption, pets or making glue. Although hunting of the species is technically illegal, it is not strictly enforced and has little effect.[5] In Dong Ampham National Protected Area in Laos on the border of Vietnam, local hunters estimated that approximately 50 red-shanked doucs are killed each year.[5] From 2015-2018, the Bach Ma National Park Forestry Protection department in Vietnam confiscated 13kg of red-shanked douc meat.[9] Their behavioral characteristics are believed to make the species particularly easy to hunt.[6] In this region, the meat of the red-shanked douc is reported as being a favorite food. Vietnam has the highest hunting levels of the species.[5]
Their other main threats are pet trade, habitat fragmentation, creation of agricultural land and military installation.[5][8]
With Laos having the biggest population of red-shanked doucs, the country has been marked as being the most important for conservation of the species.[5] A study conducted by Camille N. Z. Coudrat et al. stated that the best approach to conserving the species is to focus on the largest populations, specifically in Laos.[5] At present, there is no conservational action in Laos.[7] There have been efforts to breed red-shanked doucs in captivity since the late 1960s but they are difficult to keep in zoos due to factors such as their diet and so currently, there are only 33 individuals in captivity worldwide.[17][20]
For the population in Sơn Trà, habitat loss due to development plan poses as the biggest risk to them. Historically, Son Tra had a military installation and so many animals in the region were shot as practice targets.[8] Currently, the red-shanked doucs in Son Tra Nature Reserve are protected by the Army, Police and Forest Protection departments of Danang and Son Tra. [17]
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{{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) The red-shanked douc (Pygathrix nemaeus) is an arboreal and diurnal Old World monkey belonging to the Colobinae subfamily. They are endemic to Laos, Vietnam and Cambodia. They are known for their bright colors and express exhibit sexual dimorphism through their body size. The species have been declared critically endangered by the International Union for Conservation of Nature, with the main threats being from hunting, habitat loss and pet trade. They are one of three species in the genus Pygathrix, the other two being the black-shanked (P. nigripes) and gray-shanked (P. cinerea) doucs.
Red-shanked doucs live in fission-fusion, multilevel societies that have a mean of 18 individuals per band. They are folivorous and consume mainly Acacia pruinescens, Ficus racemosa, Millettia nigrescens, Zanthoxylum avicennae and Castanopsis ceratacantha. Their four-chambered stomachs that allow for bacterial fermentation help them with their high-fiber diet.
