Designing wildlife-vehicle conflict observation systems to inform ecology and transportation studies

Globally, wildlife-vehicle conflict (WVC) fragments wildlife populations (due to road/traffic-aversion), kills and injures individual animals, can cause wildlife population declines, may eventually contribute to local or total extinction of certain species, and can harm vehicles and drivers. Preventing WVC begins with recording locations of conflict, such as vehicle crashes, animal carcasses (roadkill), or animal behavior around roads, such as avoidance of roads or crossing-behavior. These data are ideally used to inform transportation policy and planning and to retrofit roadways and their structures to reduce WVC. We are collectively involved with or manage eight regional or national systems for reporting WVC in collaboration with volunteers and/or agency staff. In this review, we survey systems for recording WVC by volunteers and agency staff at different geographical scales, based on existing literature and our personal experience. We report the range of data collection methods, data management systems and data visualizations employed as well as discuss the groups and type of volunteers and agencies involved. We use our expertise and the global survey to provide methodological specifications based on current best-practice for collecting and using WVC data to inform transportation and conservation decisions. We conclude with a vision of next steps toward a global network of WVC reporting systems, that have clear and practical applications for improved conservation research as well as guidelines for management of road networks.