Tonkin snub-nosed monkey
Sightings of the Tonkin snub-nosed monkey have become increasingly rare. The primate was thought to be extinct until the 1990s when a small population was discovered in Na Hang District in Tuyen Quang Province of Vietnam. Heavy poaching for food as well as the wildlife blackmarket and the destruction of habitat are the main reasons why the Tonkin snub-nosed monkey is considered to be one of "The World's 25 Most Endangered Primates."
By 2008, when a small population with three infants was discovered in a remote forest, fewer than 250 of the primates were thought to exist.
- Groves, C. P. (2005). Wilson, D. E.; Reeder, D. M. eds. Mammal Species of the World (3rd ed.). Baltimore: Johns Hopkins University Press. pp. 173. OCLC 62265494. ISBN 0-801-88221-4. http://www.bucknell.edu/msw3/browse.asp?id=12100686.
- Xuan Canh, L., Khac Quyet, L., Thanh Hai, D. & Boonratana, R. (2008). Rhinopithecus avunculus. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 5 November 2008.
- Mittermeier, R.A.; Wallis, J.; Rylands, A.B. et al., eds. (2009) (PDF). Primates in Peril: The World's 25 Most Endangered Primates 2008–2010. Illustrated by S.D. Nash. Arlington, VA.: IUCN/SSC Primate Specialist Group (PSG), International Primatological Society (IPS), and Conservation International (CI). pp. 1–92. ISBN 978-1-934151-34-1. http://www.primate-sg.org/PDF/Primates.in.Peril.2008-2010.pdf.
- snub nosed monkeys
- (BBC News) " Glimmer of hope for rare monkey", 7 December 2008.