Efficacy of camera traps in detecting primates in Hue Saola Nature Reserve.

Camera trapping has been demonstrated to be an effective tool in surveying a suite of species, especially elusive mammals in rough terrains. The method has become increasingly common in primate surveys for both ground-dwelling and arboreal taxa in many tropical regions of the world. However, camera trapping has rarely been used to inventory primates in Vietnam, although many species are under severe threats and in critical need of surveying for improved conservation measures. In this study, we employed camera trapping to primarily investigate the possible continued presence of galliform species, but also to opportunistically record primate species, in Hue Saola Nature Reserve in central Vietnam. We documented five primate species, including the northern pig-tailed macaque Macaca leonina, the stump-tailed macaque Macaca arctoides, the rhesus macaque Macaca mulatta, the pygmy slow loris Nycticebus pygmaeus, and the red-shanked douc Pygathrix nemaeus, which represents a majority of primate diversity in the reserve. The results show that camera trapping may be an option for documenting primate diversity, and seasonal and daily activities of ground-dwelling taxa. Our data also suggest that although human disturbance is still rampant in the area, Hue Saola Nature Reserve appears to be reasonably well protected compared to other conservation areas in Indochina. In particular, it is home to several highly threatened primates, and it therefore plays a crucial role in primate conservation in Vietnam. However, these populations are in need of greater protection, such as more targeted patrols to remove snares and prevent other violations.