Camera-trapping reveals new insights in the ecology of three sympatric muntjacs in an overhunted biodiversity hotspot.

The Annamites ecoregion harbors exceptional levels of species richness and endemism, but intensive snaring has decimated populations of terrestrial mammals. Ungulates, such as muntjacs, are susceptible to snaring, and in need of effective conservation action. At least three muntjacs occur sympatrically in the region: the Annamite dark muntjac species complex Muntiacus rooseveltorum/truongsonensis, the northern red muntjac Muntiacus vaginalis, and the large-antlered muntjac Muntiacus vuquangensis. We conducted a landscape-scale systematic camera-trapping survey in Nakai-Nam Theun National Park to gather information on the ecology and distribution of these muntjacs. We analyzed camera-trap records within an occupancy framework to evaluate responses to environmental and anthropogenic variables, and to predict distributions across the protected area. We found varying responses to the covariates, indicating complex drivers of occurrence, though all three muntjac had higher occupancies in more inaccessible areas. Mean (95%) PAO in the protected area was higher for large-antlered muntjac (0.33 [0.22–0.49]), followed by Annamite dark muntjac (0.28 [0.18–0.39]), and then northern red muntjac (0.27 [0.15–0.42]). Large-antlered muntjac and northern red muntjac were widespread, while dark muntjac was restricted to a single high elevation area. Overall, our results provide new insights into muntjac ecology, distribution, and population status, and we discuss how this information can be used to inform conservation efforts. Given the high occupancies that we found for the Critically Endangered large-antlered muntjac, we argue that Nakai-Nam Theun National Park may be vital for the long-term survival of the species. [ABSTRACT FROM AUTHOR]