Talk Roadkill hot spots can change over the time variables explaining them do not

Road-kill studies are often carried out in a limited timescale. The assumption that their results (hot-spots and variables determining them) are maintained over time is then applied. To check the reliability of this premise, in 2014-2016 we repeated a study that we conducted in 2002-2004 in the center of Spain on the factors explaining polecat (Mustela putorious) road-kills, a species very prone to them. We found 63 polecats in 2014-2016 (ongoing) compared with 107 in 2002-2004; we used the same 104 random points in both periods. Our results show that both in 2002-2004 and in 2014-2016 the presence of rabbits (Oryctolagus cuniculus), polecat’s main prey, in the road verges was the main factor differentiating between points with casualties and random points. However, the spatial distribution of road-kills has changed in these 12 years. In the sectors where most casualties were recorded in 2002-2004, they have practically disappeared today, coinciding with a reduction in rabbit abundance there. By contrast, the road-kills have increased in sectors where prey species have increased. This has important implications for studies of road casualties as hot spots should be periodically evaluated, especially if it is suspected that variables determining them have changed.

Mustela putorious, road-kills, temporal transferability