Comparing the effectiveness of two roadkill survey methods on roads

Wildlife-vehicle collisions on linear transport infrastructure and especially on roads are potentially dangerous for drivers and cause serious economic damage. Moreover, roads cause fragmentation, creating barriers or traps that are harmful to many animal species, underlining the need to detect roadkill hotspots. However, the effectiveness of some roadkill survey methods on roads is not fully understood. The aim of this study is to conduct comparative analyses of the spatial distribution, body size totals and composition of roadkill hotspots, using data collected in a study area using two robust roadkill survey methods: i) one conducted monthly by an ecologist, ii) one conducted daily by patrollers. The results suggest that these methods are efficient in locating mortality hotspots and are complementary: they identify different body size groups, with patrollers detecting all large fauna and ecologists recording more small species. We suggest combining both methods to obtain more representative data of road mortality.