Planning conservation strategies based on a multi-scalar and multispecies approach to assess habitat connectivity and roadkill risk area

Fragmentation and habitat loss caused by human activities are among the major threats to biodiversity, acting at different spatial and temporal scales. Linear infrastructures such as roads could interrupt habitat connectivity, thus representing a serious threat to the animal population. In this study, we quantified habitat connectivity and roadkill patterns of forest mammal species in Friuli Venezia Giulia Region (NE Italy). Specifically, we aimed at i) assessing the relationship between habitat connectivity degree and roadkill risk, and, on these bases, at ii) identifying the sites where mitigation measures should be planned and those to preserve. We used a multispecies and multi-scalar (i.e., using different spatial resolutions) approach to model habitat connectivity and roadkill risk grouping species in low, medium and high mobility, based on their dispersal ability. To model the connectivity, we used Circuitscape and we created 27 scenarios for each mobility species group combining different resistance values for each land use class (setting values of minimum and maximum resistance for forest and urban areas, respectively). On the other hand, roadkill data were modelled through species distribution models and predicted for the entire road network. In this way, a roadkill risk map for each mobility species group was obtained. The overlap between areas with high conservation value (e.g., corridors) and areas with a high roadkill risk allowed the identification of priority areas that need management and restoration of habitat connectivity. The proposed approach can be used to plan effective conservation actions for different species with different dispersion capabilities.