Crested langurs
| Crested langurs | ||||||||||||
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Black crested langur ( T. auratus ) |
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| Trachypithecus | ||||||||||||
| Reichenbach , 1862 |
The lutung or Lutungs ( Trachypithecus ) are a primate species from the group of Slim monkeys within the family of Cercopithecidae . The genus comprises 20 species, making it the most species-rich genus of the slippery monkey and colobus monkey .
distribution
Crested langurs live all over Southeast Asia (from Northeast India and South China to Borneo and Bali ).
description
Crested langurs are rather slender monkeys with a long tail. The color of the fur varies depending on the species from black to gray to orange-yellow. Many species have fur markings and a lighter underside, the hair on the head is often raised in a kind of hood. Your arms are very short compared to your feet and your thumb is reduced in size. The inner surfaces of the hands and feet are hairless and allow a secure grip in the branches. These animals reach a head trunk length of 40 to 80 cm and a weight of 5 to 15 kg, with males being considerably larger than females. A bulge above the eyes and other details in the structure of the skull distinguish them from the cap langurs .
Way of life
Crested langurs are forest dwellers who are mainly found in tropical rainforests , occasionally also in lower mountain forests. They spend most of the day in the trees, where they mainly move on all fours, and they can also jump well. Compared to the sympatric cap langurs ( Presbytis ), however, they jump little. Crested langurs are diurnal with a focus on early morning and afternoon.
They live in groups of 5 to 20 animals, mostly in harem groups, which means that they are composed of one male and several females. Young males have to leave their birth group when they reach sexual maturity and sometimes join forces with others to form all-male groups. When a new male takes over a harem after defeating and driving away the old one, it often kills the children of the group. These animals are territorial, with loud shouting and, if necessary, they defend their territory against other groups with force. They know a series of sounds that they use to warn group members of predators or to point out other groups to their own territory. Mutual grooming also plays an important role.
food
Crested langurs are herbivores, they feed primarily on leaves, while fruits and buds complete their diet. To digest the hard leaves, they developed a multi-chambered stomach.
Reproduction
After a gestation period of around six to seven months, a single young is born, twins are rare. Newborns usually have a golden yellow coat. Not only the mother takes care of the offspring, but also the other females. You pass the boy around, play with him, carry him and cuddle with him while the mother is looking for food. If the mother dies, another female adopts the young animal. Crested langurs are weaned in the second half of their life and reach sexual maturity at 4 to 5 years of age. Life expectancy can only be estimated at 20 years.
threat
The clearing of the rainforests is the main problem for the crested langurs. Since they are shy of people , unlike the Hanuman langur , they avoid villages and retreat to quiet areas, if available. Several species are listed as endangered or threatened by the IUCN .
Systematics and types
The system of crested langurs is controversial and the delimitation of species and subspecies is often unclear. The following list with four generic groups follows Mittermeier, Rylands & Wilson (2013):
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cristatus group , originally only one species, T. cristatus .
Selangor langur ( T. selangorensis )- The black crested langur ( Trachypithecus auratus ) is characterized by a glossy black fur, there is also an orange-yellow color variant. He lives in Java, Bali and Lombok.
- The silver crested langur ( T. cristatus ) has a silver-gray fur. It is common in Sumatra and Borneo.
- The Germain langur ( T. germaini ) is widespread from Myanmar to Vietnam.
- The Annam langur ( T. margarita ) lives in the center of the former South Vietnam.
- The western crested langur ( T. mauritius ) occurs on western Java.
- The selangor langur ( T. selangorensis ) lives on the west coast of the Malay Peninsula.
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obscurus group
Southern spectacled langur ( T. obscurus )- The southern spectacled langur ( T. obscurus ) has a black coat with white stripes on the back and limbs. It gets its name from the white spots around the eyes. It is native to Myanmar, Thailand, and West Malaysia.
- The Tenasserim Langur ( T. barbei ) lives in the Tenasserim region in southern Myanmar and in neighboring Thailand.
- The Indochina spectacled langur ( T. crepusculus ) lives in the north of Vietnam, Laos and Thailand.
- The Phayre Spectacled Langur ( T. phayrei ) is similar to the Southern Spectacled Langur, but has a gray-brown fur. Its home is in northeast India and Bangladesh.
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pileatus group , in this group there was probably hybridization with Indian langurs ( Semnopithecus ).
Cap langur ( T. pileatus )- The cap langur ( T. pileatus ) is one of the largest species. Its upper side is dark, almost black, while its underside is colored reddish-orange. He lives in northeast India, Bangladesh, and northwest Myanmar.
- The shortridge langur ( T. shortridgei ) lives in northern Myanmar and southwest China.
- The golden langur ( T. geei ) lives in western Assam and Bhutan. It is characterized by its golden yellow fur.
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francoisi group , also called black langurs in German, are an Indochinese species group thatlivesin wooded karst areas and is the only group of Old World monkeys to use caves as sleeping places. Originally, all species in this group were onlycountedas one species ( T. francoisi ).
Tonkin black langur ( Trachypithecus francoisi )- The Tonkin black langur ( T. francoisi ) lives in southwest China, Vietnam and Laos. His fur is mainly black and he has white whiskers on his face.
- The Hatinh langur ( T. hatinhensis ) lives in a small area in Vietnam and Laos.
- The Delacour black langur or panda langur ( T. delacouri ) lives in Vietnam and is considered to be critically endangered.
- The Indochinese black langur ( T. Ebenus ) was not described until the 1990s.
- The southern black langur ( T. laotum ) is endemic to Laos.
- The white-headed langur ( T. leucocephalus ) only lives in karst regions in southern China in the Guangxi Autonomous
- The Cat Ba langur ( T. poliocephalus ) occurs with a tiny population size on the island of Cát Bà .
The South India and Sri Lanka occurring two types of so-called violettgesichtigen langurs ( Nilgiri langur ( S. johnii ) and purple-faced langur ( S. vetulus )), which also formerly in the genus Trachypithecus were asked, are now among the Indian langurs ( Semnopithecus ) and form the subgenus Kasi there . Morphological reasons speak in favor of belonging to the crested langurs, but genetic reasons clearly in favor of an allocation to the Indian langurs.
Phylogenetic system of crested langurs according to He et al. 2012
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literature
- Thomas Geissmann : Comparative Primatology. Springer-Verlag, Berlin a. a. 2003, ISBN 3-540-43645-6 .
- Russell A. Mittermeier , Anthony B. Rylands & Don E. Wilson : Handbook of the Mammals of the World: Primates: 3rd page 738, ISBN 978-84-96553-89-7 .
- Ronald M. Nowak: Walker's Mammals of the World. 6th edition. Johns Hopkins University Press, Baltimore MD 1999, ISBN 0-8018-5789-9 .
- Don E. Wilson, DeeAnn M. Reeder (Eds.): Mammal Species of the World. A taxonomic and geographic Reference. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 .
Individual evidence
- ↑ a b T. Geissmann (2003), page 221.
- ↑ Mittermeier, Rylands & Wilson (2013), pp. 561 and 740–753.
- ↑ a b Mittermeier, Rylands & Wilson (2013), p. 562.
- ↑ Mittermeier, Rylands & Wilson (2013), p. 563.
- ^ Mittermeier, Rylands & Wilson (2013), p. 561.
- ^ Martin Osterholz, Lutz Walter & Christian Roos: Phylogenetic position of the langur genera Semnopithecus and Trachypithecus among Asian colobines, and genus affiliations of their species groups. BMC Evolutionary Biology 2008, 8:58 doi: 10.1186 / 1471-2148-8-58
- ↑ Kai He, Naiqing Hu, Joseph D. Orkin, Daw Thida Nyein, Chi Ma, Wen Xiao, Pengfei Fan, Xuelong Jiang: Molecular phylogeny and divergence time of Trachypithecus : with implications for the taxonomy of T. phayrei . Zoological Research 33 (E5-6): E104-E110 doi: 10.3724 / SP.J.1141.2012.E05-06E104
