Javan Langur (Trachypithecus auratus)


MORPHOLOGY:
The dental formula of the Javan langur is 2:1:2:3 on both the upper and lower jaws (Ankel-Simons, 2000). This species has a sacculated stomach to assist in the breakdown of cellulose. The Javan langur has enlarged salivary glands to assist it in breaking down food. The palm print for the majority of individuals is of the simple loop type (Maryanto, 2000). The circumfacial hair is erect and forward-curled (Brandon-Jones, 1995). Females differ from males in having a pale, usually yellowish white, pubic patch (Brandon-Jones, 1995). Infants are orange in coloration (Rowe, 1996). Average body mass for the Javan langur is 7.1 kilograms (Rowe, 1996).

Groves (2001) describes two subspecies for the Javan langur, each having differing pelage colorations:

Brandon-Jones (1995) describes an additional subspecies:

Maryanto (2000), based on the palm and sole prints, suggests that there are not any subspecies to this species because the prints to do not show any clinal variation amongst the east, west, and central populations.

RANGE:
The Javan langur is found on the island of Java and the smaller islands of Bali and Lombok, Indonesia (Weitzel and Groves, 1985). Brandon-Jones (1995) describes a possible new subspecies from Indochina. In Pangandaran Nature Reserve, this species lives in small, dense groups, on the east side of the park, avoiding the teak plantations (Watanabe et al., 1996). However, Kool (1986) found that in the same reserve a group lived in a mixed lowland forest of secondary growth/ Tectonia grandis, Swietenia macrophylla, and Acacia auriculiformis plantation. The Javan langur was found to be rather common on Mt. Prahu, Indonesia (Nijman and van Balen, 1998). This species has been found to occur in primary and secondary forests, both in the interior and on the edge (Nijman and van Balen, 1998; Gurmaya et al., 1994). In Ujung Kulon National Park, Java, this species was found in all forest strata levels except the ground (Gurmaya et al., 1994).


ECOLOGY:
The diet of the Javan langur consists of leaves (immature and mature), fruit (ripe and unripe), flowers, flower buds, and insect larvae (Kool, 1993). Kool (1992, 1993) found that half of the dietary intake for the subspecies T. auratus sondaicus consisted of protein-rich leaves. Leaves selected for consumption had a lower fibre content, thus having a higher degree of digestibility (Kool, 1992). Young leaves of the teak tree, Tectona grandis, are an important food source for this species when favored foods are scarce (Kool, 1993, 1991). The midrib of the leaf of the teak tree is the preferred part consumed, where an individual will bend the leaf in half (from apical tip to base), holding it with one or two hands while stripping and chewing it (Kool, 1993). Kool (1993) found that 27 to 37% of the diet of the Javan langur at Pangandaran Nature Reserve was fruit, with 15 to 27% of the diet unripe fruit and 10 to 12% of the diet ripe fruit. Fruits consumed tend to have higher amounts of condensed tannins and total phenolics than leaves consumed (Kool, 1992). Tannins may be useful in the diet because they may reduce acidosis of the stomach by slowing down the rate of fermentation (Goltenboth 1976; Davies et al., 1988; Kool, 1992). A considerable part of the diet of the subpsecies T. auratus sondaicus was found to include fruits that were ripe, and ripe fruits can cause acidosis in colobines (Goltenboth, 1976; Kool, 1992). Fruits tend to be eaten for their seeds (Kool, 1993). Watanabe et al. (1996) studying the Javan langur in the Pangandaran Nature Reserve found that when tourists (Humans Homo sapiens) tried to give food to the langurs that they would not accept the food. At Pangandaran Nature Reserve Kool (1993) found that important food tree species were Ficus sinuata, Ficus sumatrana, and Vitex pinnata. Brotoisworo and Dirgayusa (1991) found that one group at Pangandaran Nature Reserve fed on soil. Kool (1993) found that at Pangandaran Nature Reserve monthly variation in diet of when specific food were eaten varied amongst differed groups, where one group consumed fruits more significantly in July, August, September, January, and February and another groups fruit was consumed more in November and December. Groups will feed simultaneously on the same food source (Kool, 1993). Individuals of the group will also eat when the rest of the group is resting or traveling (Kool, 1993). Brotoisworo and Dirgayusa (1991) found that adult males fed less frequently as compared to other group adults and subadults.

The Javan langur is a diurnal and an arboreal species. The average group size for this species is around seven individuals (V. Nijman, unpubl. data; cited in Nijman and van Balen, 1998). Kool (1991) found that groups ranged in size from 6-21 individuals with one or two adult males in the group. On Lombok Island, Indonesia, group sizes were found to be larger in secondary and monsoon forests than in tropical forests (Supriatna et al., 1986).

A major predator of the Javan langur is humans who hunt this species for commercial and food purposes (Djuwantoko, 1994).

LOCOMOTION:
The Javan langur moves through the forest quadrupedally (Rowe, 1996).

SOCIAL BEHAVIOR:
The Javan langur lives in social groups of one or two adult males (Kool, 1991). Groups on Lombok Island were found to only have one adult male (Supriatna et al., 1986). Males disperse from their natal group and will travel solitarily or in all-male groups (Kool, 1989; Bennett and Davies, 1994; Rowe, 1996). Mengantara and Dirgayusa (1994) found that males tend to maintain close proximity with other group males, females maintain close proximity with other females, the dominant group male with all group members. Adult females will engage in aggressive encounters with adult females from other groups (Mengantara and Dirgayusa, 1994). Females will care for infants from other females (allo-mothering) (Kool, 1989; Bennett and Davies, 1994; Rowe, 1996).

VOCAL COMMUNICATION:
alarm call: This call sounds like "ghek-ghok-ghek-ghok-" (Gurmaya et al., 1994).

OLFACTORY COMMUNICATION:

VISUAL COMMUNICATION:

TACTILE COMMUNICATION:

REPRODUCTION:
The Javan langur gives birth to one offspring at a time.

REFERENCES:
Ankel-Simons, F. 2000. Primate Anatomy. Academic Press: San Diego.

Bennett, E.L. and Davies, A.G. 1994. The ecology of Asian colobines. in Colobine Monkeys: Their Ecology, Behaviour and Evolution. eds. A.G. Davies and J.F. Oates. Cambridge University Press: Cambridge.

Brandon-Jones, D. 1995. A revision of the Asian pied leaf-monkeys (Mammalia: Cercopithecidae: superspecies Semnopithecus auratus), with a description of a new subspecies. Raffles Bulletin of Zoology. Vol. 43, 3-43.

Brotoisworo, E. and Dirgayusa, I.W.A. 1991. Ranging and feeding behavior of Presbytis cristata in the Pangandaran Nature Reserve, West Java, Indonesia. in Primatology Today. eds. A. Ehara, T. Kimura, O. Takenaka, and M. Iwamoto. Elsevier Science Publishers: Amsterdam.

Davies, A.G., Bennett, E.L., and Waterman, P.G. 1988. Food selection by two south-east Asian colobine monkeys (Presbytis rubicunda and Presbytis melalophos) in relation to plant chemistry. Biological Journal of the Linnean Society. Vol. 34, 33-56.

Djuwantoko. 1994. Habitat and conservation of ebony leaf monkey in deciduous forests (teak), in central Java. (abstract) XVth Congress of the International Primatological Society. Bali-Indonesia.

Goltenboth, R. 1976. Non human primates (apes, monkeys and prosimians). in The Handbook of Zoo Medicine. (translation) eds. H-G. Klos and E.M. Lang. Van Nostrand Reinhold: New York.

Groves, C.P. 2001. Primate Taxonomy. Smithsonian Institute Press: Washington, D.C.

Gurmaya, K.J., Adiputra, I.M.W., Saryatiman, A.B., Danardono, S.N., and Sibuea, T.T.H. 1994. A preliminary study on ecology and conservation of the Java primates in Ujung Kulon National Park, West Java, Indonesia. in Current Primatology Volume 1: Ecology and Evolution. eds. B. Thierry, J.R. Anderson, J.J. Roeder, and N. Herrenschmidt. Universite Louis Pasteur: Strasbourg.

Kool, K. 1986. Ranging and feeding behaviour of the silver-leaf monkey Presbytis cristata at Pangandaran, Jawa Barat, Indonesia. (abstract) Primate Report. Vol. 14, 244.

Kool, K.M. 1989. Behavioural ecology of the silver leaf monkey, Trachypithecus auratus sondaicus, in the Pangandaran Nature Reserve, West Java, Indonesia. PhD thesis, University of New South Wales, Sydney, Australia.

Kool, K.M. 1991. Behavioural ecology of the silver leaf monkey, Trachypithecus auratus sondaicus, in the Pangandaran Nature Reserve, West Java, Indonesia. (abstract) Primate Eye. Vol. 44, 19-20.

Kool, K.M. 1992. Food selection by the silver leaf monkey, Trachypithecus auratus sondaicus, in relation to plant chemistry. Oecologia. Vol. 90, 527-533.

Kool, K.M. 1993. The diet and feeding behavior of the silver leaf monkey (Trachypithecus auratus sondaicus) in Indonesia. International Journal of Primatology. Vol. 14(5), 667-700.

Maryanto, I. 2000. Variation in the ebony and silver leaf monkey (Trachypithecus auratus and T. cristatus) dermatoglyphic markers. Jurnal Primatologi Indonesia. Vol. 3(1), 17-24.

Mengantara, E. and Dirgayusa, I.W.A. 1994. Social behavior of lutung (Trachypithecus auratus sondaicus) in Pangandaran Nature Reserve. (abstract) XVth Congress of the International Primatological Society. Bali-Indonesia. Nijman, V. and van Balen, S. 1998. A faunal survey of the Dieng Mountains, central Java, Indonesia: distribution and conservation of endemic primate taxa. Oryx. Vol. 32(2), 145-156.

Rowe, N. 1996. The Pictorial Guide to the Living Primates. Pogonias Press: East Hampton, New York.

Supriatna, J., Sampurno, B.W., Sarono, S., Suwelo, I.S., and Manullang, B.O. 1986. The silver leaf monkeys (Presbytis auratus) on Lombok island, Indonesia: Troop size, population density and distribution. (abstract) American Journal of Primatology. Vol. 11, 99.

Watanabe, K., Mitani, M., Arakane, T., Gurmaya, K.J., Dirgayusa, W.A., Megantara, E.N., and Brotoisworo, E. 1996. Population changes of Presbytis auratus and Macaca fascicularis in the Pangandaran Nature Reserve, West Java, Indonesia. (abstract) Primate Research. Vol. 12, 271.

Weitzel, V. and Groves, C.P. 1985. The nomenclature and taxonomy of the colobine monkeys of Java. International Journal of Primatology. Vol. 6(4), 399-409.

Last Updated: June 20, 2007.
[The Primata] [Primate Evolution] [Primate Taxonomy] [Primate Conservation] [Primate Fact Sheets] [Primate Definitions] [Primate Store] [Trachypithecus Links]