White-headed Langur (Trachypithecus leucocephalus)


MORPHOLOGY:
This species has a sacculated stomach to assist in the breakdown of cellulose. The white-headed langur has enlarged salivary glands to assist it in breaking down food. This species has slim hands and feet and reduced thumbs. The dental formula of the white-headed langur is 2:1:2:3 on both the upper and lower jaws (Ankel-Simons, 2000). The head and body length for this species ranges from 470-615 millimeters (Groves, 2001). The tail length ranges from 765-890 millimeters (Groves, 2001). The head, shoulders, and upper chest are white in coloration (Groves, 2001). The crest on top of the head is black-tipped (Groves, 2001). The tail is white to brownish for two-thirds to three-fourths of the length (Groves, 2001). The hands and feet have some white hairs mixed with black (Groves, 2001). The thighs are colored white and white-tipped hairs mixed with black (Groves, 2001).

RANGE:
The white-headed langur is found in the country of China (Li, 2000; Weitzel and Vu, 1992). This species lives in forests around limestone hills in four counties in southwest Guangxi, China (Li, 2000; Rogers and Li, 2002). This species has been found in the Bapen Reserve (Rogers and Li, 2002; Li, 1999). Li (2000, 1999) found that the white-headed langur prefers large areas with a continuous habitat.

ECOLOGY:
The white-headed langur is a folivorous species (Li, 2000). Immature leaves are the favorite food for the white-headed langur (Li, 2000). Distribution is restricted to habitats that have preferred vegetation (Li, 2000). In high quality habitat, home ranges tend to be smaller than those found on lesser quality habitats (Li, 2000). Groups on high quality habitats are larger, have more young, and engage in social play at a higher frequency (Rogers and Li, 2002). Groups that low quality habitat tend to spend more time feeding (Rogers and Li, 2002). In the limestone hills, the bottom is used primarily for resting and feeding, the middle for moving, and the top for sunbathing in winter (Huang et al., 2000). This is an arboreal and diurnal species. Group sizes range from 5 to 9 individuals (Jiang et al., 1990). The white-headed langur sleeps in groups in caves found in the limestone hills it lives near (Li, 1993). Males lead the group movements (Li, 1993). Groups will emerge from the cave before dawn, then rest near the cave entrance before departing for foraging (Li, 1993). There are three feeding peaks during the day, on in the morning, one at just before noon, and one in the evening (Li, 1993). Li (1993) found that groups would spend 51.8% of the time during the day in trees and 48.2% of the time on the rocky substrate. The major predator of this species is humans, Homo sapiens (Li, 2002)

LOCOMOTION:
The white-headed langur moves through the forest quadrupedally (Fleagle, 1988).

SOCIAL BEHAVIOR:
The white-headed langur has a unimale social system (Li, 2000; Rogers and Li, 2002). Recent findings suggest however that some groups are switching to a multimale-multifemale social system because of habitat degradation (Li, 2002; Rogers and Li, 2002). All-male bands have been recorded that range in size from 4 to 16 individuals (Rogers and Li, 2002). Solitary individuals have also been recorded (Jiang et al., 1990). Females will disperse from their natal groups (Rogers and Li, 2002). This is a highly territorial species, with the adult males maintaining territories to attract adult females (Li, 2000).

VOCAL COMMUNICATION:

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 white-headed langur gives birth to a single offspring. Group reproduction seems to be tied to the quality of habitat available where those groups with a majority of high quality habitat reproduce and those who do not have a majority will not reproduce (Li, 2000). Jiang et al. (1990) found that the white-headed langur gives birth all year long.

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

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

Huang, C., Xue, Y., Wei, Y., and Li, Y. 2000. Habitat vegetation and selection of white-headed leaf monkey (Trachypithecus leucocephalus). Acta Theriologica Sinica. Vol. 20(3), 175-185.

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

Jiang, H., Feng, M., Wang, J., Wu, M., Lai, Y., and Liu, Z. 1990. XIIIth Congress of the International Primatological Society. Nagoya and Kyoto, Japan, 79.

Li, Z.-Y. 1993. Preliminary investigation of the habitats of Presbytis francoisi and Presbytis leucocephalus, with notes on the activity pattern of Presbytis leucocephalus. Folia Primatologica. Vol. 60, 83-93.

Li, Z.-Y. 1999. Study of conservation biology on the white-headed langur, Presbytis leucocephalus, in China. ASP Bulletin. Vol. 23(2), 6.

Li, Z.-Y. 2000. The socioecology of white-headed langurs (Presbytis leucocephalus) and its implications for their conservation. (abstract) Primate Eye. Vol. 73, 41-42.

Li, Z.-Y. 2002. Conservation action plan for white-headed langurs (Trachypithecus leucocephalus) in Guangxi, China. (abstract) XIXth Congress of the International Primatological Society. Beijing, China, 0091.

Rogers, E. and Li, Z.-Y. 2002. Effects of deteriorating habitat quality on white-headed langurs. (abstract) XIXth Congress of the International Primatological Society. Beijing, China, 0097.

Weitzel, V. and Vu, N.T. 1992. Taxonomy and conservation of Trachypithecus francoisi in Vietnam. Asian Primates. Vol. 2(2), 2-5.

Last Updated: November 7, 2003.
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