Javan leaf monkey (Lutung Jawa)Scientific classification Kingdom: AnimaliaPhylum: ChordataClass: MammaliaOrder: PrimatesSuborder: HaplorhiniInfraorder: SimiiformesFamily: CercopithecidaeSubfamily: ColobinaeGenus: TrachypithecusReichenbach, 1862
The lutungs are a group of Old World monkeys and make up the entirety of the genus Trachypithecus. Their range is split into two parts; one part is much of Southeast Asia (northeast India, southern China, Borneo, Thailand, Java, and Bali), the other part is extreme southern India and Sri Lanka. Most of the species in this genus can be referred to as lutungs, langurs, or leaf monkeys.
The name "lutung" comes from the Sundanese language and means "blackness"; it is preferred by some authors because it distinguishes the genus from the "true" langurs of the Indian subcontinent.
DescriptionLutungs have a rather slim build with a long tail. The fur color varies, depending on the species, from black and grey to orange yellow. Many species have skin designs and a brighter lower surface, the hair on the head is often compared to a hood. Their arms are very short in comparison to the feet and their thumbs are also somewhat shorter. The inner surfaces of the hands and feet are hairless so that their fur does not get caught when reaching into branches. These animals reach a length of 40 to 80 cm and a weight of 5 to 15 kg, with males generally larger than females. A bulge over the eyes and other details, primarily in the head, differentiate it from the surilis.
Habitat and behaviourLutungs live in the forests, often preferring rain forests, although occasionally they are also found in secluded mountain forests. They spend the largest part of the day in the trees, where they crawl along the branches on all fours, although they can also jump well from tree to tree. They are diurnal, although more active in the early mornings and the afternoon.
They live in groups of five to 20 animals, mostly in harems, i.e. a single male with several females. Young males must leave their birth group when fully mature, often forming bachelor groups. If a new male takes over a harem, defeating and scaring off the harem leader, he often kills the children of the group. Lutungs are territorial, with loud shouting to defend their territories from other lutung interlopers, resorting to force if the outsiders are not scared off. They have a common repertoire of sounds with which they warn group members. Also, mutual grooming plays an important role.
Lutungs are herbivores, primarily eating leaves, fruits, and buds. To digest the tough leaves, they developed a multichambered stomach.
SpeciesAs of 2005, the authors of Mammal Species of the World recognize the following Trachypithecus species:[2]Genus TrachypithecusT. vetulus groupPurple-faced langur, Trachypithecus vetulus - moved into genus SemnopithecusNilgiri langur, Trachypithecus johniiT. cristatus groupJavan lutung, Trachypithecus auratusSilvery lutung or silvered leaf monkey, Trachypithecus cristatusIndochinese lutung, Trachypithecus germainiTenasserim lutung, Trachypithecus barbeiT. obscurus groupDusky leaf monkey, Trachypithecus obscurusPhayre's leaf monkey, Trachypithecus phayreiT. pileatus groupCapped langur, Trachypithecus pileatusShortridge's langur, Trachypithecus shortridgeiGee's golden langur, Trachypithecus geeiT. francoisi groupFrancois' langur, Trachypithecus francoisiHatinh langur, Trachypithecus hatinhensisWhite-headed langur, Trachypithecus poliocephalusLaotian langur, Trachypithecus laotumDelacour's langur, Trachypithecus delacouriIndochinese black langur, Trachypithecus ebenus