Non-Volant Mammalian Diversity, Occurrence, and Ecological Patterns in a Tropical Montane Forest in Sarawak, Borneo

Mammalian species are key in maintaining a healthy ecosystem. The tropical rainforest in Borneo is characterized by its rich biodiversity and rugged interior, which houses various forest types from the lowland dipterocarp forest to the montane and ericaceous forests above 1500 m. Using the data obtained from 81 camera trap stations set up from April 2023 to September 2024, we investigated the diversity of mammalian species across the spatial and temporal dimensions. We detected 35 species of mammals from 6 orders and 15 families, excluding the Muridae and Sciuridae species. We highlight significant differences between mean species richness among tropic guilds across elevational classes. From the results of Bayesian single-season occupancy analysis, the pig-tailed macaque Macaca nemestrina has the highest occupancy rate of 0.79 (95% credible interval [CrI] 0.68, 0.89), followed by the red muntjac Muntiacus muntjak, 0.71 (95% CrI 0.59, 0.83). Temporally, all the individual species' activity patterns followed the previous studies, except for the mousedeer Tragulus spp., which are found to be mostly nocturnal. We also report evidence of differences in elevational distribution among some species within the community. In conclusion, our results offer baseline knowledge on the spatial and temporal distribution pattern of non-volant mammals in a high-altitude protected area.