Occupancy Baselines and Temporal Trends of Threatened Mammal Communities in Southeast Asian Mangroves

Mangroves and mangrove-associated wetlands provide critical refuges for elusive and threatened mammals, yet long-term population baselines are scarce. We conducted camera-trap monitoring of mammal communities in the Koh Kapik Ramsar Site and Peam Krasop Wildlife Sanctuary, coastal Cambodia, from 2017 to 2023. We deployed cameras at 20-30 sites per year, adding up to a total of 156 sites. Using a multi-species hierarchical occupancy framework, we estimated baseline occupancy and detection probabilities, habitat associations, anthropogenic effects, and temporal trends for eight mammal species. Endangered long-tailed macaque (Macaca fascicularis) and Vulnerable fishing cat (Prionailurus viverrinus) showed the highest occupancy probabilities, whereas Endangered hairy-nosed otter (Lutra sumatrana) and Critically Endangered Sunda pangolin (Manis javanica) had consistently low and uncertain occupancy. Detection probability varied markedly among species, with smooth-coated otter (Lutrogale perspicillata) being the most detectable. Species exhibited contrasting habitat associations, with fishing cats selecting back and fringe mangroves, hairy-nosed otters associated with riverine mixed mangroves, and large-spotted civets (Viverra megaspila) favoring Melaleuca swamp forests. Occupancy increased with tree cover across the community, while responses to distance from villages differed among species, indicating both tolerance and avoidance of human activity. Temporal trend analyses suggest declines in occupancy for several threatened species, including long-tailed macaque, fishing cat, smooth-coated otter, and large-spotted civet. Our results highlight the importance of mangrove-associated habitats and forest cover for mammal persistence and provide one of the first community-level baselines for evaluating and guiding conservation actions in Southeast Asian mangrove landscapes.