Current conservation status of Germain’s langur (Trachypithecus germaini) in Vietnam


Following the split of the silvered langurs of Indochina into two species based on molecular and phenotypic data, there is a need to reevaluate their distribution and update their conservation status. Here, we report the distribution and assess the population size of Germain’s langur (Trachypithecus germaini) within its known range across Vietnam. We confirmed this species at six of seven survey sites in different habitats within three provinces in the Mekong Delta Region, including semi-evergreen forest at the Seven Mountains of An Giang Province, mangrove forest in Ngoc Hien and Nam Can Districts and Melaleuca forest in U Minh Ha National Park of Ca Mau Province, and limestone forest at Kien Luong Karst Area and semi-evergreen and evergreen forests at Phu Quoc National Park of Kien Giang Province. We found no evidence of this species in Mui Ca Mau National Park, Ca Mau Province where it was previously reported. We conservatively estimate that the total population of Germain’s langurs in Vietnam consists of 362–406 individuals, with the largest population found in the Kien Luong Karst Area. Hunting and habitat loss are severely impacting Germain’s langur, resulting in the extirpation of the population in Mui Ca Mau National Park and small, isolated populations in the Seven Mountains and Ngoc Hien and Nam Can Districts. However, the ability of this species to inhabit a wide range of forest types, and its increasing population sizes in Phu Quoc National Park and Kien Luong Karst Area, provide signs of hope that continued conservation actions may help in its long-term survival.

This is a preview of subscription content, log in to check access.

Fig. 1


  1. Ang A (2017) Genetic variability, diet metabarcoding, and conservation of colobine primates in Vietnam. PhD Dissertation, University of Colorado Boulder

  2. Baird IG, Ha DD (1996) Primates in Vietnam. IPPL News 23:9–12

  3. Baker LR (1999) The plight of Vietnam’s primates. IPPL News 26:15–21

    Google Scholar 

  4. Blair ME, Sterling EJ, Hurley MM (2011) Taxonomy and conservation of Vietnam’s primate: a review. Am J Primatol 73:1039–1106

    Article  Google Scholar 

  5. Buckland ST, Anderson DR, Burnham KP, Laake JL (1992) Distance sampling: estimating abundance of biological populations. Chapman and Hall, London

    Google Scholar 

  6. Government of Vietnam (1996) Decree no. 47-CP of August 12, 1996, of the government on the management of weapons, explosives and support instruments (in Vietnamese)

  7. Groves CP (2001) Primate taxonomy. Smithsonian Institution Press, Washington, DC

    Google Scholar 

  8. Haus T, Vogt M, Forster B, Vu NT, Ziegler T (2009) Distribution and population densities of diurnal primates in the karst forests of Phong Nha-Ke Bang National Park, Quang Binh Province, Central Vietnam. Int J Primatol 30:301–312

    Article  Google Scholar 

  9. Hoang MD, Tran VB, Covert HH, Luu HT (2010) Conservation status of primates in Ta Kou Nature Reserve. In: Nadler T, Rawson BM, Van NT (eds) Conservation of primates in Indochina. Frankfurt Zoological Society and Conservation International, Hanoi, pp 91–98

    Google Scholar 

  10. Hoang MD, Covert HH, Roos C, Nadler T (2012a) A note on phenotypical and genetic differences of silvered langurs in Indochina (Trachypithecus germaini and T. margarita). Vietnamese J Primatol 2:47–54

    Google Scholar 

  11. Hoang MD, Nguyen TT, Covert HH, Tran VB, Luu HT (2012) Conservation status of the Indochinese silvered langur in Vietnam. In: XXIV Congress of the International Primatological Society, Cancun, Mexico, pp 371–372 (Abstract no. 402)

  12. IUCN (2016) The IUCN Red List of threatened species. Version 2016-1. <>. Downloaded on 30 June 2016

  13. Le KQ, Nguyen VK (2010) Preliminary survey on primates in Phu Quoc National Park, Kien Giang Province, Viet Nam. In: Nadler T, Rawson BM, Van NT (eds) Conservation of primates in Indochina. Frankfurt Zoological Society and Conservation International, Hanoi, pp 99–106

    Google Scholar 

  14. Li Y, Li D (1998) The dynamics of trade in live wildlife across the Guangxi border between China and Vietnam during 1993–1996 and its control strategies. Biodivers Conserv 7:895–914

    Article  Google Scholar 

  15. Moody JE, Dara A, Coudrat CNZ, Evans T, Gray T, Maltby M, Soriyun M, Hor NM, O’Kelly H, Bunnat P, Channa P, Pollard E, Rainey HJ, Rawson BM, Vann R, Chansocheat S, Setha T, Sokha T (2011) A summary of the conservation status, taxonomic assignment and distribution of the Indochinese silvered langur Trachypithecus germaini (sensu lato) in Cambodia. Asian Primates J 2:21–28

    Google Scholar 

  16. Nabhitabhata J, Chan-ard T (2005) Thailand red data: mammals, reptiles and amphibians. Office of Natural Resources and Environmental Policy and Planning, Bangkok

    Google Scholar 

  17. Nadler T (2015) The critical status of the Delacour’s langur (Trachypithecus delacouri) and the call for a national action plan. Vietnam J Primatol 2:1–12

    Google Scholar 

  18. Nadler T, Brockman D (2014) Primates of Vietnam. Endangered Primate Rescue Center, Cuc Phuong National Park, Vietnam

    Google Scholar 

  19. Nadler T, Momberg F, Nguyen XD, Lormee N (2003) Leaf monkey. Frankfurt Zoological Society—Cuc Phuong National Park Conservation Program, Fauna & Flora International, Vietnam Program

  20. Nadler T, Walter L, Roos C (2005) Molecular evolution, systematics and distribution of the taxa within the silvered langur species group (Trachypithecus [cristatus]) in Southeast Asia. Zool Gärten (NF) 75:238–247

    Google Scholar 

  21. Nadler T, Vu NT, Streicher U (2007) Conservations status of Vietnam primates. Vietnam J Primatol 1:7–26

    Google Scholar 

  22. Phu Quoc National Park (2007) Operational Management Plan of Phu Quoc National Park from 2007 to 2011 (in Vietnamese). Techincal Report to Vietnam Conservation Fund, p 28

  23. Ratajszczak R (1989) Notes on the current status and conservation of primates in Vietnam. Primate Conserv 9:134–136

    Google Scholar 

  24. Roos C, Vu NT, Walter L, Nadler T (2007) Molecular systematics of Indochinese primates. Vietnam J Primatol 1:41–53

    Google Scholar 

  25. Roos C, Nadler T, Walter L (2008) Mitochondrial phylogeny, taxonomy and biogeography of the silvered langur species group (Trachypithecus cristatus). Mol Phylogenet Evol 47:629–636

    CAS  Article  PubMed  Google Scholar 

  26. Roos C, Boonratana R, Supriatna J, Fellowes JR, Groves CP, Nash SD, Rylands AB, Mittermeier RA (2014) An updated taxonomy and conservation status review of Asian primates. Asian Primates J 4:2–38

    Google Scholar 

  27. Ross C, Reeve N (2003) Survey and census methods: population distribution and density. In: Setchell JM, Curtis DJ (eds) Field and laboratory methods in primatology: a pratical guide, vol 6. Cambridge University Press, Cambridge, pp 90–109

    Google Scholar 

  28. Thomas L, Buckland ST, Rexstad EA, Laake JL, Strindberg S, Hedley SL, Bishop JRB, Marques TA, Burnham KP (2010) Distance software: design and analysis of distance sampling surveys for estimating population size. J Appl Ecol 47:5–14. doi:10.1111/j.1365-2664.2009.01737.x

    Article  PubMed  PubMed Central  Google Scholar 

  29. Timmins RJ, Steinmetz R, Poulsen MK, Evans TD, Duckworth JW, Boonratana R (2011) The Indochinese silvered leaf monkey Trachypithecus germaini (sensu lato) in Lao PDR. Primate Conserv 26:1–12

    Google Scholar 

Download references


This project was funded by the Vietnam Academy of Science and Technology with the project title: “Research on current conservation status and habitat of the Indochinese silvered langur Trachypithecus germaini (Milne-Edwards 1876); propose conservation plan” (No. VAST.ĐLT.09/14-15). We would like to express our gratitude to the Southern Institute of Ecology for administrative assistance. We also thank the management board of Phu Quoc National Park, U Minh Ha National Park, and the Department of Agriculture and Rural Development of each province for permission to conduct surveys. Moreover, we also express our appreciation to the local people who contributed information to this project. Finally, we would like to express our thanks to Dr. Ramesh Boonratana and an anonymous reviewer for their valuable comments and edits.

Author information



Corresponding author

Correspondence to Bang Van Tran.

About this article

Verify currency and authenticity via CrossMark

Cite this article

Van Tran, B., Nguyen, M.A., Nguyen, D.Q. et al. Current conservation status of Germain’s langur (Trachypithecus germaini) in Vietnam. Primates 58, 435–440 (2017).

Download citation


  • Colobine
  • Distribution
  • Population size
  • Presence/absence method
  • Best count