Germain's langur (Trachypithecus germaini)

Also known as: Germain’s silver langur, Germain’s silver leaf monkey, Indochinese lutung, Indochinese silvered langur
GenusTrachypithecus (1)
SizeHead-body length: 49 - 59 cm (2) (3)
Tail length: 72 - 84 cm (2) (3)

Classified as Endangered (EN) on the IUCN Red List (1) and listed on Appendix II of CITES (4).

Germain’s langur is a long-tailed, tree-dwelling monkey (5), with dark to medium grey upperparts and slightly paler underparts. The individual dark hairs have short, creamy tips, giving a slightly grizzled appearance. The hands and feet are black, the forearms are dark grey, and the tail is black above and lighter below, while the black face is framed by long, whitish-grey, whisker-like hairs, forming a distinctive “halo” (2) (3) (6) (7). The top of the head bears a short, pointed crest, and prominent brow ridges give the appearance of permanently raised eyebrows (5) (8). The female has a whitish pubic patch (7). In contrast to the adult, the coat of the infant is bright orange (2) (5) (6) (8). Germain’s langur was previously considered a subspecies of the silvery lutung, Trachypithecus cristatus (1) (3), but can generally be distinguished by its lighter colour, larger size, longer tail, and by genetic differences (3) (7).

Germain’s langur occurs in southeast Thailand, Cambodia (west of the Mekong River), southern Vietnam, Myanmar, and southern Lao People’s Democratic Republic (1) (2) (3) (9). However, the precise limits of the species’ distribution are unclear. Two subspecies are sometimes recognised, Trachypithecus germaini germaini and T. g. caudalis (1) (3) (9), while a third, T. c. margarita, found to the west of the Mekong River, is now considered to be a distinct species (1) (10).

Germain’s langur mainly inhabits lowland forest, occurring in evergreen, semi-evergreen, mixed and riverine forest habitats (1) (2).

Little information is available on the biology of Germain’s langur. However, like other members of the genus, it is likely to spend most of its time in the trees, feeding on a diet of leaves, fruit and flowers (2) (5) (8). A large, specialised stomach containing symbiotic bacteria enables this group of monkeys to digest leaf material more efficiently than any other primates, and also to detoxify otherwise poisonous leaves (2) (5). Details of the social and reproductive behaviour of Germain’s langur are lacking, but it is likely that, as in related species, it lives in small groups containing a single adult male, and gives birth to a single infant around every two years (8).

Although a relatively widespread species, Germain’s langur is very rare throughout most of its range (1) (3), and its population is believed to have more than halved in recent decades (1). The major threats to the species are hunting, for food, medicine and the pet trade, and habitat loss, mainly due to clearance for agriculture (1) (2) (3).

Germain’s langur occurs in a number of protected areas, including Phu Quoc and Cat Tien National Parks in Vietnam (1), and Phnom Samkos Wildlife Sanctuary in Cambodia (11). International trade in the species should be regulated under its listing on Appendix II of the Convention on International Trade in Endangered Species (CITES) (4), and it is legally protected in Vietnam, although greater enforcement of the laws, as well as additional measures to control hunting and wildlife trade, are urgently needed. Increased environmental education and the development of sustainable alternatives to forest destruction have also been proposed to protect the region’s primates (3). Specific conservation measures recommended for Germain’s langur include further research and survey work to better understand the species’ status, distribution, and taxonomic relationships with related forms (1) (3).

For more information on the conservation of Germain’s langur and other wildlife in the region see:

To find out more about primate conservation see:

Authenticated (06/05/10) by Matthew Richardson, primatologist and author.

  1. IUCN Red List (January, 2010)
  2. Francis, C.M. (2008) A Field Guide to the Mammals of South-East Asia. New Holland Publishers Ltd, London.
  3. Nadler, T., Momberg, F., Dang, N.X. and Lormée, N. (2003) Vietnam Primate Conservation Status Review 2002. Part 2: Leaf Monkeys. Fauna & Flora International - Vietnam Program and Frankfurt Zoological Society, Hanoi, Vietnam. Available at:
  4. CITES (January, 2010)
  5. Macdonald, D.W. (2006) The Encyclopedia of Mammals. Oxford University Press, Oxford.
  6. Endangered Primate Rescue Center (January 2010)
  7. Richardson, M. (May, 2010) Pers. comm.
  8. Nowak, R.M. (1991) Walker’s Mammals of the World. The Johns Hopkins University Press, Baltimore and London.
  9. Wilson, D.E. and Reeder, D.M. (2005) Mammal Species of the World. A Taxonomic and Geographic Reference. Third Edition. The Johns Hopkins University Press, Baltimore. Available at:
  10. Roos, C., Nadler, T. and Walter, L. (2008) Mitochondrial phylogeny, taxonomy and biogeography of the silvered langur species group (Trachypithecus cristatus). Molecular Phylogenetics and Evolution, 47: 629-636.
  11. Coudrat, C.N.Z. and Nekaris, K.A.I. (2009) First diurnal primate survey in Samkos Wildlife Sanctuary, Cardamom Mountains, Southwest Cambodia, during the wet season. Folia Primatologica, 80: 155-156.