A forecasting map of avian roadkill-risk in Europe: A tool to identify potential hotspots

Abstract In this study, we propose a novel strategy for identifying potential hotspots of avian roadkills in Europe. The proposed approach combines information about the spatial distribution of bird species at a comparatively higher risk of roadkill with data on road density. First, using a large dataset collected from several European studies and reports, we extracted the frequency of occurrence of bird casualties for 209 breeding bird species recorded in roadkill events. We standardized the relative frequency of roadkill from 0 (species never recorded in bird casualties' reports) to 1 (species with the higher number of roadkill's), obtaining a continuous variable that indicates the potential risk of roadkill species by species. Second, using published data on the spatial distribution of breeding bird species in Europe, we calculated the cumulative risk of roadkill in each bird assemblages, by considering the sum of the values estimated for each species in the previous step. Third, we calculated the road density in each spatial unit. Finally, we elaborate a forecasting map of potential avian roadkill-risk across Europe, by combining the data on road density and cumulative roadkill risk of bird communities. The tool proposed can help to identify potential hotspots at different spatial scales where the risk of avian roadkill is high, offering the possibility to improve conservation measures in road planning. Briefly, the prediction of where there is aligned convergence between communities with highly ranked species and landscapes with dense road networks can be used in procedures modelling wildlife-car collisions, for transportation mitigation projects.