A real disaster.
Several million wild animals perish each year on French roads, victims of a collision with a vehicle.
Mammals, reptiles, amphibians, birds, bats, all are affected.
“The most emblematic are surely the hedgehog, which rolls up into a ball when it is frightened and is therefore particularly vulnerable, as well as foxes, badgers, or large game, whose collisions are a problem for human safety.
But the damage is also important for less visible fauna, such as bats or salamanders.
For certain threatened species, the impact can even be very strong, like the lynx and the wolf”, explains Stéphanie Morelle, Biodiversity project manager for the France nature environment (FNE) associative network.
If it is not new, the phenomenon has for several years aroused a growing awareness of the authorities.
Infrastructure developments, which allow animals to continue their movements without risking their skin, are beginning to multiply.
On the motorway network, a pioneer in the field, but now also on the secondary network.
Ecobridges, tunnels, benches, rope ladders…
“Things have changed since Nicolas Hulot’s Biodiversity Plan  and the implementation of the “avoid, reduce, offset” principle , observes Stéphanie Morelle.
We see a variety of devices.
We are talking about ecobridges, ecoducts, tunnels, aerial bridges to force bats to fly high, benches under structures for otters and beavers, rope ladders for squirrels…”
Loire-Atlantique is one of those few departments that have recently decided to tackle the problem head-on.
Some 250 new infrastructure developments are thus announced by 2027 by the new socialist majority.
One million euros is dedicated to them this year.
Basically, a very precise inventory of mortality, with counting of corpses over one year, was carried out with environmental associations.
The conclusion is clear.
“At least 1,081 animals were killed in the 20 km sector studied.
Extrapolating to the scale of the road network managed by the department, this makes more than 230,000 animal victims of collisions per year.
It's quite huge.
Amphibians seem to be the most threatened, their population is collapsing,” reports Chloé Girardot-Moitié, vice-president of the Loire-Atlantique departmental council.
Rethink maintenance, hedge trimming, waterways
Specific facilities (tunnels, artificial banks, 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 nest to review how to maintain bridges, we rethink the size of hedges so as not to disturb nesting and the species that find refuge there, we carry out work on certain bridges or locks to allow fish farming continuity… This subject must be gradually integrated everywhere in our infrastructures”, says Chloé Girardot-Moitié.
Wishing to “disseminate good practices”, Loire-Atlantique has also published guides for municipalities, which are even eligible for subsidies if they are part of the process.
“All of this is going in the right direction,” rejoices the Biodiversity project manager for France nature environnement.
Afterwards, we must not forget the monitoring and evaluation of these systems.
Sandrine Morelle insists.
“The eco-bridges, for example, we know that there are places where it doesn't 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.
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