Assessing banteng recovery in west-central Thailand by using camara trapping-based spatially explicit mark–resight with natural marking

Context Banteng (Bos javanicus) is critically endangered and declining in Asia. The largest remaining population in mainland Southeast Asia occurs in Huai Kha Khaeng (HKK), which is a part of Thailand’s Western Forest Complex that also supports a large carnivore source population. Management of banteng and other large ungulates is critical to large carnivore recovery in Southeast Asia. However, current ungulate density estimates have wide variances that make it difficult to evaluate the effectiveness of ongoing management efforts. Aims We deployed 38 camera-traps from December 2021 to February 2022 (dry season) and June to August 2022 (wet season) at a 97 km2 site to evaluate banteng management activities in HKK. Methods We employed a spatial mark–resight method using camera-trap images reviewed by three independent observers to increase the precision of banteng density estimates. Key results On the basis of 2600 trap-days during the dry season and 2704 trap-days during the wet season, the banteng mean density estimate was 881–932 individuals per 100 km2 in the dry season and 462–481 per 100 km2 in the wet season. Among age classes, adults had the highest density, followed by juveniles, young adults and calves. Conclusions Our density estimate was higher and had a lower variance than do previous prey distance sampling estimates that are currently used in Thailand, indicating that HKK supports a large banteng population and represents a key area for the future conservation of banteng in Southeast Asia. Implications The results from this study strongly argue for using a consistent, standardized monitoring methodology to assess the recovery efforts of this and other key tiger prey species.