Brook S.M.,WWF Vietnam |
van Coeverden de Groot P.,Queen's University |
Scott C.,Queen's University |
Boag P.,Queen's University |
And 9 more authors.
Biological Conservation | Year: 2012
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. © 2012 Elsevier Ltd.
Brook S.M.,WWF Vietnam |
Dudley N.,University of Queensland |
Dudley N.,Equilibrium |
Mahood S.P.,WCS Cambodia |
And 5 more authors.
Biological Conservation | Year: 2014
The extinction of the Javan rhinoceros (Rhinoceros sondaicus) from Vietnam in 2010 was a conservation tragedy. Hunting has been the primary driver of the catastrophic decline of Javan rhinoceros throughout its range. The last individual from Vietnam was poached in 2010. To help avert repeating such outcomes with similarly imperiled species, this case study presents a state-pressure-response framework, considering the rhinoceros's historical and current status, the pressures it faced, and the adequacy of the conservation response. The failure at the site level to protect the rhinoceros population ultimately resulted in its demise. Low political will to take decisions required to recover the species and inadequate focus from the conservation and donor community further contributed to the subspecies's extinction, in part due to a lack of knowledge on population status. Lessons from this example should inform the conservation of other very threatened large vertebrates, particularly in Southeast Asia. © 2014 Elsevier Ltd.
Gray T.N.E.,WWF Greater Mekong |
Nguyen Quang H.A.,WWF Vietnam |
Nguyen Van T.,Hue University
Biodiversity and Conservation | Year: 2014
Given the crisis facing South-east Asian biodiversity evidence led conservation, including assessing the impact of innovative protected area management models, is urgently needed. Bayesian statistics provide an intuitive way to interpret biodiversity monitoring data but are largely unused, or poorly understood, by field biologists and protected area managers. We built Bayesian occupancy models for two threatened endemics of the Annamite mountains: northern yellow-cheeked gibbon Nomascus (gabriellae) annamensis and crested argus Rheinardia ocellata ocellata based on auditory surveys in three protected areas in central Vietnam. Occupancy of 2 × 2-km grid cells across the landscape was 0.76 ± SE 0.03 for northern yellow-cheeked gibbon and 0.68 ± SE 0.05 for crested argus. Models predicted higher probability of gibbon occurrence at lower elevations and higher probability of crested argus presence with increasing dense forest cover. Bayesian modeling is a useful tool for assessing the effectiveness of conservation interventions and for measuring progress against conservation goals. The wider application of Bayesian statistics in conservation monitoring should allow more intuitive and user-friendly representation of sampling uncertainty, including visual representation of probability distributions and more rigorous testing for changes in the status of conservation targets. © 2014 Springer Science+Business Media Dordrecht.