Hanuman Langur (Semnopithecus entellus)

MORPHOLOGY: The average body mass for an adult male hanuman langur is between 9 and 20 kilograms, and for the female it is between 7.5 and 18 kilograms. The pelage color for this species ranges from gray to brown (Fleagle, 1988). This species has a sacculated stomach to assist in the breakdown of cellulose. RANGE: The hanuman langur is found in the countries of Bangladesh, Bhutan, Burma, China, India, Nepal, and Pakistan. This species is found in a variety of habitats, including scrublands, rainforests, and in cities; the hanuman langur regularly is found in urban areas.

ECOLOGY: The hanuman langur is a folivorous species, but will also consume fruits, flowers, and cultivated crops. In some populations cultivated crops and "hand-outs" from people constitute a large portion of the diet. They can eat the seeds and the fruit from the Strychnos plant which is toxic to humans. This species forages mostly in the early morning and just before nightfall. The hanuman langur is a semi-terrestrial and diurnal species. LOCOMOTION: The hanuman langur moves through the forest and on the ground quadrupedally (Fleagle, 1988). The hanuman langur also uses a leaping gait through the forest (Fleagle, 1988).

SOCIAL BEHAVIOR:
The social system of the hanuman langur varies upon location and can be either unimale or multimale-multifemale. Multimale-multifemale troops can have a size up to 125 individuals. In unimale troops the resident male is under constant pressure from other males attempting to take over the troop. When a group of males takes over a troop they will kill the infants and one male will establish himself as the resident male (Strusaker and Leland, 1987). It has been noted that the new male will mate with the females shortly after takeover (Sugiyama, 1965; Mohnot, 1971; Vogel and Loch, 1984). Males may kill infants because they gain a reproductive advantage, this because females will go into estrus shortly after the lose of their infants (Hrdy, 1974). Females allow other females to hold and to care for their young (allomothering). All-male troops are found in this species.

VOCAL COMMUNICATION:
whoop: This call is given by the adult male of the troop. This call is emitted before troop movements, and functions to maintain group cohesion.

OLFACTORY COMMUNICATION:

VISUAL COMMUNICATION:

TACTILE COMMUNICATION:
social grooming: This is when one individual grooms another and is used to reinforce the bonds between individuals.

REPRODUCTION:
The hanuman langur gives birth to a single offspring.

head-shaking: This is where the female shakes her head back and forth before she presents to the male.

presenting: This behavior is performed by the female to elicit a copulation from the male; this pattern tells the male that she is ready for copulation (Estes, 1991). Head-shaking: precedes this display.

REFERENCES:
Burton, F. 1995. The Multimedia Guide to the Non-human Primates. Prentice-Hall Canada Inc.

Estes, R.D. 1991. The Behavior Guide to African Mammals. University of California Press.

Fleagle, J. G. 1988. Primate Adaptation and Evolution. Academic Press.

Hrdy, S.B. 1974. Male-male Competition and Infanticide Among the Langurs (Presbytis entellus) of Abu Rajasthan. Folia Primatologica, Vol. 22, 19-58.

Mohnot, S.M. 1971. Some Aspects of Social Changes and Infant-killing in the Hanuman Langur (Presbytis entellus) (Primates: Cercopithecidae) in Western India. Mammalia, Vol. 35, 175-198.

Struhsaker, T.T. and Leland, L. 1987. Colobines: Infanticide by Adult Males. In Primate Societies. eds. B.B. Smuts, D.L. Cheney, R.M. Seyfarth, R.W. Wrangham, and T.T. Struhsaker. University of Chicago Press.

Sugiyama, Y. 1965. On the Social Change of Hanuman Langurs (Presbytis entellus) in Their Natural Conditions. Primates, Vol. 6, 213-247.

Vogel, C. and Loch, H. 1984. Reproductive Parameters, Adult-male Replacements, and Infanticide Among Free-ranging Langurs (Presbytis entellus) at Jodhpur (Rajasthan), India. In Infanticide: Comparative and Evolutionary Perspectives. eds. G. Hausfater and S.B. Hrdy. Aldine, Hawthorne, N.Y.

Last Updated: October 15, 2003.
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