A real disaster. Millions of wild animals die every year on French roads, victims of a collision with a vehicle. Mammals, reptiles, amphibians, birds, bats, all are affected. “The most emblematic are certainly the hedgehog, which rolls into a ball when frightened and is therefore particularly vulnerable, as well as foxes, badgers or big game, whose collision is a problem for human safety. But the damage is also important for less visible fauna, such as bats or salamanders. For certain endangered species, the impact can even be very strong, like the pilot and the wolf, ”explains Stéphanie Morelle, biodiversity project manager for the French natural environment (FNE) associative network.
If this is not new, the phenomenon has attracted increasing attention among the authorities for several years. Infrastructure development, which allows animals to continue their movements without risking their skin, is beginning to multiply. On the highway network a pioneer in the field, but now also on the secondary network.
Eco-bridges, tunnels, benches, rope ladders …
“Things have been moving since Nicolas Hulot’s biodiversity plan  and the implementation of the principle of “avoid, reduce, equalize”. , notes Stephanie Morelle. We see a number of different devices. We are talking about eco-bridges, ecoducts, tunnels, air bridges to force bats to fly high, benches under structures for otters and beavers, rope ladders for squirrels … “
The Loire-Atlantique is one of the few departments that has recently decided to tackle the problem directly. Thus, around 250 new infrastructure developments are announced by 2027 by the new socialist majority. One million euros is dedicated to them this year.
Basically, a very accurate inventory of mortality has been made, with the counting of corpses over a year, with environmental associations. The conclusion is clear. “At least 1,081 animals were killed in the surveyed 20 km sector. If you extrapolate to the extent of the road network that the department manages, more than 230,000 animals fall victim to collisions a year. It’s quite large. Amphibians appear to be the most endangered, their population is collapsing, ”reports Chloé Girardot-Moitié, Vice-President of the Loire-Atlantique Branch Council.
Rethink maintenance, hedge trimming, waterways
Specific facilities (tunnels, artificial widths, footbridges) have therefore been devised on a case-by-case basis with the associations depending on crossing habits. But the approach goes further. “We identify the areas where bats breed to review how to maintain bridges, we reconsider the size of hedges so as not to disturb the clearing and the species that take refuge there, we perform work on certain bridges or locks to allow continuity in fish farming … This issue must be gradually integrated throughout our infrastructure, ”says Chloé Girardot-Moitié.
With a desire to “spread good practice”, the Loire-Atlantique has also issued guides to municipalities, which are even eligible for grants if they are part of the process.
“All of this is going in the right direction,” said the biodiversity mission manager for France’s natural environment. Afterwards, we must not forget the monitoring and evaluation of these systems. insists Sandrine Morelle. “The eco-bridges, for example, we know that there are places where it does not work. Either because the location is ultimately not good, or because the predators adapt their behavior while waiting for the mammals to come out of the bridge to eat them. There is not a single answer, but several solutions. And it is necessary to adapt. »