Fine-scale variation in the medium and large-sized mammal assemblage composition in northeastern Amazon: Drivers of β-diversity and species interactions

Understanding fine-scale assemblage composition patterns of mammals is important to increase ecological knowledge and support conservation actions. We investigated whether beta-diversity of medium and large-sized mammals and its components (replacement and richness difference) are related to distance to major rivers, height above the nearest drainage (HAND), and vegetation height; and whether species interactions shape their spatiotemporal distribution. We used camera traps to monitor the mammal assemblage of the Tumucumaque Mountains National Park, Northeastern Amazon. The difference (Delta) in distance to major rivers and geographic distance between sites affected positively the total beta-diversity and both its components. Delta Vegetation height affected total beta-diversity and species replacement, while Delta HAND affected richness differences, and to a lower extent, species replacement. We found evidence that spotted pacas (Cuniculus paca) and ocelots (Leopardus pardalis) adjust their spatiotemporal dynamics to escape from predation and to overlap with abundant prey, respectively. However, we did not find evidence that competition affects the spatiotemporal distribution of any other species. Vegetation height, distance to rivers and HAND influenced mammal assemblages probably through shaping the quality and amount of resources. Predation risk seems to be important in shaping the use of time and space by prey, while the distribution of prey is important for the use of time and space for predators. Furthermore, other niche differentiation mechanisms may explain why competition did not affect the species' spatiotemporal dynamics. We highlight the need to include different environmental contexts within protected areas to promote mammal diversity and conservation. The difference (Delta) in distance to major rivers, in vegetation height, in height above the nearest drainage and geographic distance between sites affected the beta-diversity of Amazonian mammals, indicating that the quality and amount of resources may be shaping the fine-scale distribution of medium and large-sized mammals in northeastern Amazon. We provided evidence that predation affects the spatiotemporal dynamics of prey and predators, but we did not find evidence that competition affects the spatiotemporal distribution of mammals. image