Factors determining roadkills in a mammal carnivore are road-type specific

Abstract

Roads threaten the conservation of many wildlife species. Carnivores are one of the most susceptible groups due to their habitat requirements. We explored the roadkill patterns of European polecats (Mustela putorious) on motorways and roads to investigate if these patterns depend on road type, a research topic frequently neglected in the literature. We studied 85 roadkills on motorways and 73 on roads, and the corresponding number of random points with no roadkills in every road type. We characterized them with 7 habitat and 7 road-related variables. Roadkill sites were significantly associated with the abundance of rabbit burrows. However, this effect was stronger on motorways, as they provide more suitable habitat for the establishment of prey species on their wider rights-of-way, or on the road interchange islands, which provide wide unused spaces. In contrast, road interchange islands on conventional roads that are simple intersections and have narrower rights-of-way. Furthermore, roadkills occurred in areas with lower agricultural cover. Thus, natural habitats on roadsides could act as alternative foraging areas for this carnivore increasing their roadkill risk. Our results showed the need to consider the characteristics such as the availability of prey or the surrounding habitat, as well as intrinsic characteristics of the road type when studying wildlife roadkills as the road-type-mediated patterns demand-specific mitigation measures.