Spatial predictors and species' traits: evaluating what really matters for medium-sized and large mammals in the Atlantic Forest, Brazil

Habitat loss and the conversion of natural environments to anthropogenic land uses are among the main drivers of biodiversity decline worldwide. The remaining habitats are inserted in highly modified landscapes, presenting contrasting patch and landscape features. Understanding species' responses to these anthropogenic land-use changes is essential for informing conservation planning. We evaluate which spatial predictors (measured at the patch and landscape scales) and species' life-history traits best predict the occurrence of medium-sized and large mammals in forest fragments of the threatened Atlantic Forest of South America. We gathered occurrence data for 36 medium-sized and large mammal species recorded by camera traps, distributed over 220 forest fragments spanning the entire Atlantic Forest biome. Species were classified according to their characteristics as follows: 'hunted forest-dependent', 'non-hunted forest-dependent', and 'generalist' species. Further, each species' occurrence was related to spatial predictors and life-history trait variables. We revealed a severe defaunation of forest mammals occurring in most forest fragments in the Atlantic Forest. Landscapes containing large forest patches, low road density, and high human population density harboured high numbers of mammal species, including those exhibiting greater body mass. Nevertheless, mammal groups diverge in their sensitivity to landscape changes. Hunted forest-dependent species mainly occurred in landscapes with lower edge density and numbers of patches and with less anthropogenic disturbance, while non-hunted forest-dependent species mainly occupied large forest fragments. Finally, generalist species also occurred in landscapes with low edge density and number of patches, but were more prevalent in landscapes with higher human population density. We stress the importance of maintaining large forest fragments, considering the effects of landscape configuration on conservation strategies, and reducing anthropogenic disturbances to ensure a greater persistence of mammal species in the Atlantic Forest.