Habitat suitability vs landscape connectivity determining roadkill risk at a regional scale: a case study on European badger (Meles meles)

Collisions between wildlife and vehicles represent the main conflict between infrastructures and ecosystems. Road mortality is the largest single cause of death for many vertebrates, representing a growing phenomenon of remarkable dimension. Most studies in road ecology investigated spatial roadkill patterns, showing that roadkill probability is often higher near optimal habitat for a large amount of species. Landscape connectivity has been less often considered in roadkill research, and only few studies considered habitat suitability and landscape connectivity at the same time. The purpose of the present study was to evaluate the relative importance of habitat suitability and landscape connectivity in determining roadkill risk for a habitat-generalist carnivore, namely, the Eurasian badger in the Abruzzo region (Central Italy). We collected occurrence data of living individuals from camera trapping and roadkill data of through a Citizen Science initiative. We used the occurrence data to produce a habitat suitability model (HSM) and a landscape connectivity model (LCM). Both HSM and LCM were then used as predictors in combination with road characteristics to fit a roadkill risk model. We found that landscape connectivity was more important than habitat suitability in determining roadkill risk for the Eurasian badger. Overall, the density of regional roads was the most important variable. Our finding highlighted how important is to consider landscape connectivity in planning mitigation measures aimed to preserve habitat-generalist species.