Heterogeneity in mesocarnivore occupancy highlights the complexity of biodiversity changes in a threatened ecoregion

Mesocarnivores are sensitive to global environmental changes, thereby serving as valuable sentinel species for assessing the ecological effects of anthropogenic disturbances. In human-modified landscapes, understanding mesocarnivore community structure and species habitat use is useful for guiding conservation strategies and preserving key ecosystem functions and services. Using camera-trap data, we evaluated the occupancy and detection probabilities of mesocarnivore assemblages in two protected areas of the Atlantic Forest, northeastern Brazil: RPPN Estação Veracel (sustainable-use) and Pau Brasil National Park (strictly protected). Ten mesocarnivore species were recorded, with higher species richness and occupancy rates in the strictly protected area. Occupancy and detection probabilities varied substantially among species and over time, with no strong responses to site-scale covariates. Nasua nasua was favored in sites with larger tree basal area, while Cerdocyon thous avoided these sites. Didelphis aurita was more common in sites distant from roads, contrasting with C. thous. All species, particularly Leopardus sp. and N. nasua, tended to use areas near reserve boundaries. Despite the high species diversity, low average occupancy suggests barriers limiting population growth, with some species benefiting from anthropogenic disturbance, underscoring the complexity of mesocarnivore roles in tropical ecosystems.