The Species Most Frequently Killed on Europe's Roads

A study identifies the species most vulnerable to road accidents—and they are not necessarily the ones most at risk of extinction. It shows that road accident prevention measures are not tailored to species conservation.   Each year, an average of 194 million birds and 29 million mammals are killed on European roads. Road densities in Europe are among the highest in the world. Fifty percent of the continent is within 1.5 km of a paved road or railroad track. Road networks therefore pose a significant threat to wildlife and could even lead to the complete extinction of certain species. To better understand the issues at stake, a new study identifies the most vulnerable species by analyzing 90 road accident investigations across 24 European countries. Which are most at risk? Small animals that reach maturity quickly and have high population densities. Nocturnal species, primarily herbivores, are also at risk of excessive road-related mortality.

According to this ranking, the blackbird and the soprano pipistrelle—a small species of bat—are the primary victims of road accidents.

The research reveals that the species killed most frequently are not necessarily the ones most at risk of extinction. Yet today, the primary factor considered when designing new roadways is a species’ mortality rate, rather than its risk of extinction. As a result, conservation efforts are directed toward the wrong species—not the ones that are most vulnerable. Wildlife conservation measures implemented during the construction of new roads are therefore not necessarily appropriate. Better understanding which species are most vulnerable to roads is therefore important if we want to take more effective conservation measures. We must go beyond quantifying road mortality by applying population models to identify species that may be vulnerable to further population loss, which will provide more precise information for targeting road segments that require mitigation measures. This consideration is all the more important given that the lockdown and reopening measures in response to COVID-19 will have disrupted wildlife. The reduction in road traffic has likely been beneficial, but the return to normalcy could take animals by surprise—particularly young animals, who are most at risk—and thus lead to a significant resurgence in mortality. Please be especially vigilant during this time.