Semnopithecus is a genus of Old World monkeys native to the Indian subcontinent, with all species with the exception of two being commonly known as gray langurs. Traditionally only the species Semnopithecus entellus was recognized, but since about 2001 additional species have been recognized. The taxonomy has been in flux, but currently eight species are recognized.
The purple-faced langur, also known as the purple-faced leaf monkey, is a species of Old World monkey that is endemic to Sri Lanka. The animal is a long-tailed arboreal species, identified by a mostly brown appearance, dark face and a very shy nature. The species was once highly prevalent, found in suburban Colombo and the "wet zone" villages, but rapid urbanization has led to a significant decrease in the population level of the monkeys. It had traditionally been classified within the genus Trachypithecus but was moved to the genus Semnopithecus based on DNA evidence indicating that is it more closely related to the gray langurs.
The Colobinae or leaf-eating monkeys are a subfamily of the Old World monkey family that includes 61 species in 11 genera, including the black-and-white colobus, the large-nosed proboscis monkey, and the gray langurs. Some classifications split the colobine monkeys into two tribes, while others split them into three groups. Both classifications put the three African genera Colobus, Piliocolobus, and Procolobus in one group; these genera are distinct in that they have stub thumbs. The various Asian genera are placed into another one or two groups. Analysis of mtDNA confirms the Asian species form two distinct groups, one of langurs and the other of the "odd-nosed" species, but are inconsistent as to the relationships of the gray langurs; some studies suggest that the gray langurs are not closely related to either of these groups, while others place them firmly within the langur group.
Trachypithecus is a genus of Old World monkeys containing species known as lutungs, langurs, or leaf monkeys. Their range is much of Southeast Asia.
Presbytis is a genus of Old World monkeys also known as langurs, leaf monkeys, or surilis. Members of the genus live in the Thai-Malay Peninsula, on Sumatra, Borneo, Java and smaller nearby islands.
The Nilgiri langur is a langur. This primate has glossy black fur on its body and golden brown fur on its head. It is similar in size and long-tailed like the gray langurs. Females have a white patch of fur on the inner thigh. It typically lives in troops of nine to ten monkeys. Its diet consists of fruits, shoots and leaves. The species is classified as vulnerable due to habitat destruction and poaching for its fur and flesh, the latter believed to have aphrodisiac properties.
The Hatinh langur is a highly threatened Old World monkey found in limestone forests in Vietnam, primarily in the Quảng Bình Province. A recent survey discovered a small population living in the Quảng Trị Province. Contrary to its name, it is not known from the Hà Tĩnh Province. The local Van Kieu minority refer to this monkey as the 'Con Cung', which roughly translates as "black, cliff-dwelling monkey with a long tail". It resembles the closely related François' langur, but its white cheek-stripes typically extend behind the ears onto the nape, and the overall black colour is non-glossy and has a brownish tinge.
The Cat Ba langur, also known as the golden-headed langur, is a critically endangered species of langur endemic to Cát Bà Island, Vietnam. It is among the rarest primates in the world, and possibly the rarest primate in Asia, with population size estimated at less than 70 individuals.
The Javan surili is a vulnerable species of Old World monkey endemic to the western half of Java, Indonesia, a biodiversity hotspot. Other common names by which it is known by include gray, grizzled or Sunda Island surili; grizzled or stripe-crested langur; Javan grizzled langur; grizzled, Java or Javan leaf monkey; langur gris.
The northern plains gray langur, also known as the sacred langur, Bengal sacred langur and Hanuman langur, is a species of primate in the family Cercopithecidae.
The Indochinese black langur is a poorly known Old World monkey native to Laos and adjacent Vietnam. It was originally described as a subspecies of T. auratus, but was later found to be a member of the T. francoisi group, with some maintaining it as a subspecies of that species. In 2001, it was recommended treating it as a separate species.
Southern plains gray langur was the common name ascribed to Semnopithecus dussumieri by Mammal Species of the World in 2005. Along with several other Semnopithecus, it had been previously considered a subspecies of the northern plains gray langur, Semnopithecus entellus, i.e., Semnopithecus entellus dussumieri. Subsequent genetic research has revealed that Semnopithecus dussumieri is an invalid taxon. These monkeys live in groups in forests and other rural habitats, with some groups being habituated to human contact and feeding. They are herbivorous, feeding by day mainly on foliage, fruits and flowers, and sleeping at night high in a tree.
The Nepal gray langur is a gray langur endemic to the Himalayas in Nepal, far southwestern Tibet, northern India, northern Pakistan, Bhutan and possibly Afghanistan. It is found in forests at an elevation of 1,500 to 4,000 metres. Its easternmost limit in India is Buxa Tiger Reserve in northern West Bengal, at least up to the Rydak river.
The Kashmir gray langur is an Old World monkey, one of the langur species. It is a leaf-eating monkey.
The Tarai gray langur is an Old World monkey, and was formerly considered a subspecies of the northern plains gray langur. The species is listed as near threatened, as there are probably not many more than 10,000 mature individuals, and it is experiencing a continuing decline.
The tufted gray langur, also known as Madras gray langur, and Coromandel sacred langur, is an Old World monkey, one of the species of langurs. This, like other gray langurs, is mainly a leaf-eating monkey. It is found in southeast India and Sri Lanka. It is one of three Semnopithecus species named after characters from The Iliad, S. hector and S. ajax being the others. In Sinhala it is known as හැලි වදුරා.
The western purple-faced langur, also known as the north lowland wetzone purple-faced langur, is a subspecies of purple-faced langur endemic to Sri Lanka. It lives in the wet zone in western Sri Lanka around the former capital city of Colombo. This subspecies are known to live in tropical rainforest, specifically in an area of Sri Lanka, where it is noted to rain two times more compared to the neighboring region. The subspecies is generally gray-brown with lighter whiskers, a gray rump patch, and dark forearms and legs. These monkeys also have dark brown or black, hairless faces. Their hands and feet are also hairless. When infants, their fur is medium brown to light gray, however it changes to their darker adult colors at between 12 and 16 weeks old. Typical length is between 48 and 67 centimetres excluding tail, with a 59 to 85 centimetres tail. On average, males weigh 8.5 kilograms (19 lb) and females weigh 7.8 kilograms (17 lb). Their average life span is about 26 years if the monkey was held in captivity. Due to their leafy diet, the western purple-faced langur back teeth, include high crowns and pointed cusps to make eating through greenery simpler. They also developed a digestive system that would allow them to break down cellulose in the leaves they eat. Although, leaves are their primary source of food, they also eat fruits and flowers. Female langurs hold a pregnancy for 195–210 days, and after the birth the offsprings are taken closely cared for by the mother until they are about 12–20 weeks old.
Miller's langur, also known as Miller's grizzled langur or Kutai grey langur, is a species of leaf monkey. It is endemic to East Kalimantan on the island of Borneo in Indonesia. It is one of the world's most endangered primates, and was at one time thought to be extinct, until it was rediscovered in 2012.
The white-headed langur is a Critically Endangered species of langur endemic to Guangxi, China.
