Indochinese grey langur

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Indochinese grey langur
Trachypithecus crepusculus, Indochinese grey langur - Loei Province (31109170388).jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Haplorhini
Infraorder: Simiiformes
Family: Cercopithecidae
Genus: Trachypithecus
Species:
T. crepusculus
Binomial name
Trachypithecus crepusculus
(Elliot, 1909)
Trachypithecus crepusculus T phayrei area.png
Indochinese grey langur range in red
Synonyms

T. phayrei crepuscula

The Indochinese grey langur (Trachypithecus crepusculus) is a species of Old World monkey native to East and Southeast Asia.

Contents

Taxonomy

It was formerly considered conspecific with Phayre's leaf monkey (T. phayrei), but a 2009 study found it to be a distinct species and the most basal member of the T. obscurus lineage, which contains several other species. [2] Later studies have also found it to be a hybrid species originating from ancient hybridization between ancestral obscurus-group langurs and the Tenasserim lutung (T. barbei). [3] [4] [5]

Distribution

This species is found throughout Indochina, from northern Thailand east to Vietnam and west to eastern Myanmar, and ranges north to southern China south of the Salween River. [4]

Habitat and ecology

Unlike langurs that live in karst forests, which have a largely terrestrial lifestyle, the Indochinese grey langur inhabits old-growth evergreen forests and has a largely arboreal lifestyle. [6]

Threats

This species' population is only thought to have about 2,400 to 2,500 mature individuals. It is threatened by habitat destruction and, especially in Vietnam and Laos, hunting, the latter of which is thought to have led to rapid declines in the species. [4]

Related Research Articles

<span class="mw-page-title-main">Douc</span> Genus of Old World monkeys

The doucs or douc langurs make up the genus Pygathrix. They are colobine Old World monkeys, native to Southeast Asia, which consists of these 3 species: red-shanked douc, black-shanked douc, and gray-shanked douc.

<i>Trachypithecus</i> Genus of Old World monkeys

Trachypithecus is a genus of Old World monkeys containing species known as lutungs, langurs, or leaf monkeys. Their range is much of Southeast Asia.

<span class="mw-page-title-main">Hatinh langur</span> Species of Old World monkey

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.

<span class="mw-page-title-main">Silvery lutung</span> Species of Old World monkey

The silvery lutung, also known as the silvered leaf monkey or the silvery langur, is an Old World monkey. It is arboreal, living in coastal, mangrove, and riverine forests in Peninsular Malaysia, Sumatra, Borneo, Java, and other nearby islands.

<span class="mw-page-title-main">Gray-shanked douc</span> Species of Old World monkey

The grey-shanked douc langur is a douc species native to the Vietnamese provinces of Quảng Nam, Quảng Ngãi, Bình Định, Kon Tum, and Gia Lai. The total population was estimated at 550 to 700 individuals in 2004. In 2016, Dr. Benjamin Rawson, Country Director of Fauna & Flora International's Vietnam Programme, announced a discovery of an additional population including more than 500 individuals found in Central Vietnam, bringing the total population up to approximately 1000 individuals.

<span class="mw-page-title-main">Black-shanked douc</span> Species of Old World monkey

The black-shanked douc is an endangered species of douc found mostly in the forests of Eastern Cambodia, with some smaller populations in Southern Vietnam. The region they are mostly found in is called the Annamite Range, a mountainous area that passes through Cambodia and Vietnam. Its habitat is mostly characterized by evergreen forest in the mountains, in the middle to upper canopy. They move around quadrupedally and by brachiation up in the trees. This species is unique with its coloration among the doucs as it has a bluish face with yellow rings around its eyes a blue scrotum and a pink penis. Like other doucs, this specie has a tail as long as its body and head length. Black-shanked douc have been observed in groups ranging from 3 to 30 individuals, depending on their habitat. Group tend to have a fission-fusion dynamic that changes with food availability. Their diet varies from dry to wet season. Regardless of the season, their diet consists mostly of leaves, but they have also been found to consume considerable amounts of fruits and flowers during wet season. The species changed conservation status in 2015 from endangered to critically endangered in the IUCN Red List of Endangered Species. This reassessment is due to an increase of the rate of population decline. No global population estimate exists. The majority of the population can be found in Cambodia, with smaller populations in Vietnam. In fact, the Wildlife Conservation Society reports almost 25,000 individuals in Cambodia's Keo Seima Wildlife Sanctuary, a population that has remained stable over the last decade. The largest populations estimated to be in Vietnam is around 500-600 individuals. The biggest challenges that the black-shanked douc faces in terms of conservation are habitat loss and illegal poaching. Conservation efforts are being made to control illegal poaching and trade in Vietnam by putting laws against hunting and trading threatened species.

<span class="mw-page-title-main">Tenasserim lutung</span> Species of Old World monkey

The Tenasserim lutung is a species of Old World monkey. It is found in Myanmar and Thailand.

<span class="mw-page-title-main">Delacour's langur</span> Species of Old World monkey

Delacour's langur or Delacour's lutung is a critically endangered species of Old World monkey endemic to northern Vietnam. It is named for French-American ornithologist Jean Théodore Delacour.

<span class="mw-page-title-main">François' langur</span> Species of Old World monkey

François' langur, also known as Francois' leaf monkey, the Tonkin leaf monkey, or the white side-burned black langur is a species of Old World monkey and the type species of its species group. It is one of the least studied of the species belonging to the Colobinae subfamily.

<span class="mw-page-title-main">Cat Ba langur</span> The rarest monkey in Asia

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.

<span class="mw-page-title-main">Phayre's leaf monkey</span> Species of Old World monkey

Phayre's leaf monkey, also known as Phayre's langur, is a species of Old World monkey native to South Asia and Southeast Asia, namely India, Bangladesh, and Myanmar. Populations from further east are now thought to belong to other species. It is listed as Endangered on the IUCN Red List and is threatened by hunting and loss of habitat. The species epithet commemorates Arthur Purves Phayre.

<span class="mw-page-title-main">Laotian langur</span> Species of Old World monkey

The Laotian langur or white-browed black langur is a species of primate in the family Cercopithecidae. It is endemic to Laos. Its natural habitat is subtropical or tropical dry forests. Genetically the Indochinese black and Hatinh langurs are very close to the Laotian langur, and consequently it has been suggested they should be considered subspecies of it.

<span class="mw-page-title-main">Dusky leaf monkey</span> Species of Old World monkey

The dusky leaf monkey, also known as the spectacled langur, or the spectacled leaf monkey is a species of primate in the family Cercopithecidae. It is found in Peninsular Malaysia, Myanmar and Thailand, and can occasionally be found in Singapore. During the day, these small, folivorous primates divide in sub-groups and forage for vegetation and fruit throughout the tropical forests. According to the IUCN, the dusky leaf monkey's population is declining due to habitat loss, poaching, and anthropogenic land use, which prompted the IUCN to classify the species as endangered in 2015.

<span class="mw-page-title-main">Germain's langur</span> Species of Old World monkey

Germain's langur is a Old World monkey native to Thailand, Myanmar, Cambodia, Laos and Vietnam. The monkey was previously included in Trachypithecus cristatus and Trachypithecus villosus.

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.

<span class="mw-page-title-main">Annamese langur</span> Species of Old World monkey

The Annamese langur is an Old World monkey from the Colobinae subfamily. It was formerly considered a subspecies of Trachypithecus germaini until it was elevated to a separate species by Roos and Groves in 2008. Its fur is lighter in colour than that of Trachypithecus germaini. Its range includes parts of Cambodia, Laos and Vietnam.

<span class="mw-page-title-main">Popa langur</span> Species of mammal

The Popa langur is a species of primate in the family Cercopithecidae. It occurs only in Myanmar and was named after Mount Popa, where a population of 100 of the monkeys live. It is listed as Critically Endangered on the IUCN Red List, as the wild population is thought to comprise 200 to 250 mature individuals.

The Shan State langur is a subspecies of primate in the family Cercopithecidae. It is found in eastern Myanmar and southwest China. While it is typically considered a subspecies or even a synonym of Phayre's leaf monkey, it is sometimes listed as a full species.

References

  1. Yongcheng, L.; Nadler, T. & Quyet, L.K. (2021). "Trachypithecus crepusculus". IUCN Red List of Threatened Species . 2021: e.T136920A204397334. Retrieved 18 November 2021.
  2. Nadler, Tilo. "Evolutionary History and Phylogenetic Position of the Indochinese Grey Langur (Trachypithecus Crepusculus)". Vietnamese Journal of Primatology.
  3. Roos, Christian; Liedigk, Rasmus; Thinh, Van Ngoc; Nadler, Tilo; Zinner, Dietmar (2017-12-18). "The Hybrid Origin of the Indochinese Gray Langur Trachypithecus crepusculus". International Journal of Primatology. 40 (1): 9–27. doi:10.1007/s10764-017-0008-4. ISSN   0164-0291. S2CID   11460634.
  4. 1 2 3 Quyet, Le Khac; Nadler, Tilo; Group), L. Yongcheng (IUCN SSC Primate Specialist (2015-11-21). "IUCN Red List of Threatened Species: Trachypithecus crepusculus". IUCN Red List of Threatened Species.
  5. Parks, Creative Commons Attribution-ShareAlike 4 0 International Thai National. "Trachypithecus crepusculus, Indochinese grey langur". Thai National Parks. Retrieved 2021-11-18.
  6. Ma, Chi; Xiong, Wei-Guo; Yang, Li; Zhang, Lu; Tomlin, Peter Robert; Chen, Wu; Fan, Peng-Fei (2020-07-18). "Living in forests: strata use by Indo-Chinese gray langurs (Trachypithecus crepusculus) and the effect of forest cover on Trachypithecus terrestriality". Zoological Research. 41 (4): 373–380. doi:10.24272/j.issn.2095-8137.2020.047. ISSN   2095-8137. PMC   7340518 . PMID   32390372.