Delacour's langur
Delacour's langur | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Primates |
Suborder: | Haplorhini |
Infraorder: | Simiiformes |
Family: | Cercopithecidae |
Genus: | Trachypithecus |
Species group: | Trachypithecus francoisi group
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Species: | T. delacouri[1]
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Binomial name | |
Trachypithecus delacouri[1] (Osgood, 1911)
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Delacour's langur range |
Delacour's langur or Delacour's lutung (Trachypithecus delacouri) is a
Physical description
Delacour's langur is somewhat larger than its two closest relatives, François' langur and the Laotian langur, but in other respects has a similar appearance. Adults measure from 57 to 62 cm (22 to 24 in) in head-body length, with a tail 82 to 88 mm (3.2 to 3.5 in) long. Males weigh between 7.5 and 10.5 kg (17 and 23 lb), while the females are slightly smaller, weighing between 6.2 and 9.2 kg (14 and 20 lb). Their fur is predominantly black, with white markings on the face and distinctive creamy-white fur over the rump and the outer thighs, while females also have a patch of pale fur in the pubic area. Like other closely related lutungs, Delacour's langur has a crest of long, upright, hair over the forehead and crown; this is, however, somewhat taller and narrower than in other species.[3][4]
Distribution and habitat
Delacour's langur is
Behaviour
Delacour's langurs are
In previous decades, Delacour's langurs were reported to live in troops of up to 30 individuals, often including a mix of males and females, although single-male groups are more common, and some small all-male groups have also been reported. In more recent years, the typical group size seems to be much smaller, with only about four to 16 members each. Males defend the troop's territory from outsiders, often standing watch on rocky outcrops. When potential rivals are spotted, the males in a troop initially try to intimidate them with loud hoots and visual displays, resorting to chasing and fighting if this fails. Within the group, social bonds are maintained by grooming and play.[3]
Despite living in forested habitats, Delacour's langurs are primarily terrestrial, only occasionally venturing into the trees. They swing by their hands when travelling through trees, and use their tails for balance when scrambling over steep rocky terrain, which may allow them to move more rapidly than other related lutungs.[3]
Reproduction
Females give birth to a single young after a
Conservation
The population of Delacour's langurs has declined rapidly in recent years. As of 2006, only 19 populations were known, following a dramatic decline in the total population of approximately 20% between 1999 and 2004.[7] Since that time, two of the populations have been extirpated, and only that in the Van Long Nature Reserve may still be large enough to remain viable.[3]
Classified as
References
- ^ OCLC 62265494.
- ^ . Retrieved 19 November 2021.
- ^ doi:10.1644/880.1.
- ^ Groves, C. (2007). "Speciation and biogeography of Vietnam's primates" (PDF). Vietnamese Journal of Primatology. 1 (1): 27–40. Archived from the original (PDF) on 2011-09-30. Retrieved 2011-11-12.
- ^ Workman, C.; Dung, L.V. (2009). "The chemistry of eaten and uneaten leaves by Delacour's langurs (Trachypithecus delacouri) in Van Long Nature Reserve, Vietnam" (PDF). Vietnamese Journal of Primatology. 1 (3): 29–36. Archived from the original (PDF) on 2012-04-01.
- S2CID 21816554.
- ISBN 978-1-934151-34-1. Archived from the original(PDF) on 2011-07-23.
- ^ "Primates in Peril - The World's Most Endangered Primates 2014-2016" (PDF). IUCN. Retrieved 6 June 2016.