Comparison of ecological, biological and anthropogenic causes of wildlife–vehicle collisions among three large herbivore species

Abstract Abstract Wildlife–vehicle collisions are of increasing concern in modern societies caracterized by a continous and accelerating anthropogenic development. Preventing and mitigating collisions with wildlife will require a better understanding of the environmental and biological drivers of collision risks. Because species of large mammals differ in terms of food requirements, habitat selection and movement behaviours, and of activity patterns we tested whether vehicle collisions with red deer, roe deer and wild boar, the most abundant large herbivores in Europe, differed in terms of spatial distribution and explanatory factors, using a Bayesian statistical framework. From 20,275 documented collisions in 9 departments of France between years 1990 and 2006, we found marked differences in magnitude and in the most influential environmental factors accounting for the density of collisions among the three species, in agreement with their biology and habitat preferences. The effect of road density was higher for the red deer than for the two other species for which it was similar, and did not level off at our large spatial-scale of observation. As expected from particle collision models, the annual hunting harvest – interpreted as a proxy of population abundance – was positively associated with the density of collisions for all species, being the strongest for red deer. Overall, the effect of landscape structure on the density of collisions was weak but while the collision density did decrease with the proportion of forest in a management unit for wild boar, it increased with the fragmentation of forests for red deer that commute among forest patches between day and night. To reduce the number of wildlife–vehicle collisions actively, our results suggest to generalise road fencing for highways and motorways or a reduction of abundance of large herbivore populations as efficient action means. Overall, we call for of a greater consideration of the species’ biology in information campaigns or by using specific road signs.