|Scientific Name:||Trachypithecus francoisi (Pousargues, 1898)|
Trachypithecus francoisi (Pousargues, 1858) ssp. francoisi
|Taxonomic Notes:||There is some interbreeding with T. poliocephalus leucocephalus south and east of the River Zuo in Guangxi, China (Groves 2001).|
|Red List Category & Criteria:||Endangered A2cd ver 3.1|
|Assessor(s):||Bleisch, B., Manh Ha, N., Khat Quyet, L. & Yongcheng, L.|
|Reviewer(s):||Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)|
Listed as Endangered as there is reason to believe the species has declined by at least 50% over the past 36 years (3 generations, given a generation length of 12 years) due primarily to habitat loss and hunting.
|Previously published Red List assessments:|
|Range Description:||This species occurs in southern China (Chongqing, Guangxi and Guizhou provinces and Chongqing Municipality in Sichuan province), and northeastern Viet Nam. It is found from the Song Hong (Red River) in Viet Nam across the Chinese border as far as the Daming Hills in Guangxi, and about 25°N 105°E in Guizhou (Groves 2001).|
Native:China; Viet Nam
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species is widespread, but populations are highly fragmented and isolated. There is no reliable population estimate for Viet Nam, but they are not likely to number more than 500 individuals there; no subpopulation contains more than 50 mature individuals (Nadler et al. 2003). In China, in the southern part of the range (Guangxi Province), the largest population is estimated at 75 individuals in Nonggang Nature Reserve (Li et al. 2007). In the northern part of the range, the largest population is in Mayanghe Nature Reserve, where the population is estimated at roughly 700 individuals. The population estimate for 2003 in China was 1,400-1,650 individuals (Lou et al. in litt.).|
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||This species is found in semi-tropical monsoon and moist tropical and subtropical rainforests in limestone (karst) areas (Marsh 1987), though not in cone karsts. The animals utilize the cave formations and overhangs in these areas as shelter from weather, and for refuge. It ranges in elevation up to 1,500 m. |
Like other Trachypithecus, T. francoisi is mostly folivorous, with the remainder of its diet consisting of shoots, fruits, flowers, and bark. Males and females reach sexual maturity in five and four years, respectively. Litter size is usually one, and birth intervals for this species are recorded at about 20 months (Nadler et al. 2003).
|Major Threat(s):||In Viet Nam, the major threat to this species is hunting, although some populations face pressures from mining and other resource extraction in the karst hills (Nadler et al. 2003). Hunting mainly takes place for traditional “medicines” and to a lesser degree for meat (feeding predominantly Chinese restaurant markets). The isolation of populations due to habitat fragmentation taking place for agricultural development (rice paddies, maize) also threatens the genetic viability of small populations in Viet Nam (Nadler et al. 2003). In Guangxi province, China, the threat of hunting is extremely severe, due to the illegal production of “black ape wine,” which is made specifically from this species; the animals are even imported illegally from Viet Nam for this purpose. Throughout the range in China, populations are threatened by habitat loss due to local cultivation and firewood extraction (Li et al. in prep.). Unmanaged fires that spread into limestone karst habitats also result in the loss of habitat.|
This species is listed on CITES Appendix II. Since the 1980s, in China, it has been listed as a Category I species under the Wildlife Protection Act, 1989.
In Viet Nam it occurs in several protected areas, including two national parks. At least two protected areas have been established specifically for this species: Sinh Long-Lung Nhoi Species and Habitat Conservation Area (Tuyen Quang Province) and Nam Xuan Lac Species and Habitat Conservation Area (Bac Kan Province).
In China it is found in 21 protected areas, three of which are national level (Lou et al. in litt.) Also, it is legally protected from hunting, though it faces additional threats there from unrestricted resource extraction and habitat disturbance (Hu et al. 2004). There is a successful captive-breeding program for this species now underway in China in Wushou (Nadler et al. 2003).
Gibson, D. and Chu, E. 1992. Management and behaviour of the Francois’ langur Presbytis francoisi francoisi at the Zoological Society of San Diego. International Zoo Yearbook 31: 184–191.
Groves C. 2001. Primate Taxonomy. Smithsonian Institution Press, Washington, DC, USA.
Hu, G., Dong, X., Wei, Y., Zhu, Y. and Duan, X. 2004. Evidence for a decline of Francois’ langur Trachypithecus francoisi in Fusui Nature Reserve, south-west Guangxi, China. Oryx 38(1): 48–54.
Li, Y., Huang, C., Ding, P., Tang, Z. and Wood, C. 2007. Dramatic decline of the Francois’ langur (Trachypithecus francoisi) in Guangxi Province, China and its conservation challenges. Oryx.
Marsh, C. W. 1987. A framework for primate conservation priorities on Asian moist tropical forests. In: C. W. Marsh and R. A. Mittermeier (eds), Primate Conservation in the Tropical Rain Forest, Liss, New York, USA.
Ma, S., Wang, Y. and Poirier, P. E. 1989. Taxonomy and distribution of the Francois’ langur (Presbytis francoisi). Primates 30(2): 233–240.
Nadler, T., Momberg, F., Nguyen Xuan Dang and Lormée, N. 2003. Vietnam Primate Conservation Status Review 2002. Part 2: Leaf Monkeys. Fauna and Flora International- Vietnam Program and Frankfurt Zoological Society, Hanoi, Vietnam.
Nadler, T., Streicher, U. and Ha Thang Long. 2004. Conservation of primates in Vietnam. Haki Publishing, Hanoi, Vietnam.
Weitzel, V. and Vu, N. 1992. Taxonomy and conservation of Trachypithecus francoisi in Vietnam. Asian Primates 2(2): 2–5.
|Citation:||Bleisch, B., Manh Ha, N., Khat Quyet, L. & Yongcheng, L. 2008. Trachypithecus francoisi. The IUCN Red List of Threatened Species 2008: e.T39853A10277000.Downloaded on 11 December 2017.|