Saturday, January 5, 2013

[Mammalogy • Extinct] Integrated and novel survey methods for rhinoceros populations confirm the extinction of Rhinoceros sondaicus annamiticus from Vietnam | Javan Rhino Officially Extinct In Vietnam

A Javan rhino in Vietnam captured in a camera-trap photo.
 ©WWF-Greater Mekong


Javan rhinoceros (Rhinoceros sondaicus) is among the most threatened large mammal species in the world. Development of rigorous, non-invasive survey techniques is a high priority, to monitor populations and develop informed conservation management strategies. The critically endangered javan rhinoceros until recently survived in two separate populations, one in Vietnam and one in Indonesia, representing distinct subspecies. The range of the annamiticus subspecies around Cat Tien National Park (CTNP) has declined significantly since its re-discovery in 1989, and no accurate estimate of population size had ever been obtained. We employed integrated survey techniques and analyses to determine the population status of the javan rhinoceros in Vietnam. We conducted a comprehensive field survey of the Cat Loc sector of CTNP using scat detection dogs to detect javan rhinoceros dung between October 2009 and April 2010. Twenty-two dung samples were collected for microsatellite DNA analysis, seventeen of which were of sufficient quality to be analysed. The genotyping work confirmed that only a single rhinoceros was present at the start of the survey in 2009 and that this was the same individual that was found dead in April 2010. Although far less definitive than host genotyping, stool bacterial diversity assays also supported the hypothesis that all samples collected by the survey were from one individual. This empirical data combined with field survey data indicate the extinction of the javan rhinoceros in Vietnam. We conclude by discussing the developmental progress of these non-invasive survey techniques to monitor other endangered rhinoceros populations. 

Highlights ► We conduct a comprehensive survey of the javan rhinoceros population in Vietnam. ► Genetic and faecal bacterial diversity analysis of faecal samples is employed. ► Rhinoceros sondaicus is confirmed extinct in Vietnam. ► We evaluate these survey and analytical techniques for monitoring rhino populations. 

Keywords: Bacterial diversity assay; Extinction; Genetic analysis; Javan rhinoceros; Rhinoceros population monitoring; Scat detection dogs

A camera trap photograph of a Javan rhino in Cat Tien Nationak Parl.
 (Photo: WWF / Cat Tien National Park)

It’s Official: Vietnam’s Javan Rhino Is Extinct. Which Species Is Next? 
Poachers and lack of territory have killed off these amazing rhinos in Vietnam. Can we save the 35 left in Indonesia?

DNA analysis of rhino dung in Vietnam's Cat Tien National Park in 2009 found that only one rhino remained at that time — the same one that was shot a year later, according to a study published recently in the journal Biological Conservation

The conservation group the World Wildlife Fund declared the rhino extinct in 2011, but it wasn't until late 2012 that the aforementioned study was published in a peer-reviewed journal with data showing that the animal is extinct in Vietnam.

Javan Rhino Officially Extinct In Vietnam via @LiveScience

S.M. Brook, P. van Coeverden de Groot, Scottb, P. Boag, B. Long, R.E. Ley, G.H. Reischer, A.C. Williams, S.P. Mahood, Tran Minh Hien, G. Polet, N. Cox, Bach Thanh Hai. 2012. Integrated and novel survey methods for rhinoceros populations confirm the extinction of Rhinoceros sondaicus annamiticus from Vietnam. Biological Conservation.155, October 2012. 59–67.