The status of Vulnerable gaur Bos gaurus and Endangered banteng Bos javanicus in Ea So Nature Reserve and Yok Don and Cat Tien National Parks, Vietnam

The wild buffaloes, gaur Bos gaurus and banteng Bos javanicus. , are among the most threatened mammals in Vietnam but little information is available on their status and distribution. Over 2004-2007 I undertook surveys in three Vietnamese distribution strongholds of the Vulnerable gaur and Endangered banteng: Ea So Nature Reserve and Yok Don and Cat Tien National Parks. A total of 22 herds with 121 gaur and seven herds with 49 banteng were observed. Herd sizes of both species were generally lower than those recorded in Thailand and Malaysia. Most of the herds were observed in remote areas, showing that the species are probably staying away from areas with human activity. No banteng were found in Cat Tien National Park. Of the other wild buffalo species the Critically Endangered kouprey Bos sauveli and Endangered water buffalo Bubalus arnee were not observed in the three protected areas but the Near Threatened serow Capricornis milneedwardsii was occasionally observed in all three areas. Illegal hunting, habitat degradation and disturbance appear to be the most significant threats to gaur and banteng in the areas surveyed. It is essential to have effective law enforcement to eliminate human impacts on these two species, and an adequate conservation strategy to secure their long-term survival.