A unique conservation effort in Switzerland is using a fixed fence to protect a vulnerable bird species, the European roller, from predators. The project, a first for the country, aims to boost the dwindling population of the birds by providing a safe nesting environment.
The number of European rollers in Switzerland plummeted from over 1,000 breeding pairs in the 1970s to just 83 in 2005, and the species even disappeared entirely from the Three Lakes region. The decline is attributed to agricultural changes, including draining wetlands for farmland and the increasing use of heavy machinery.
“Back then, they disappeared because we started draining all the fields that used to be real marshes here,” explained Lucas Lombardo, head of the European roller conservation project at Birdlife Switzerland, on Saturday. “Then, the intensification of agriculture, with larger, faster, and heavier machines, only completed the degradation of the bird’s environment.”
Boosting Breeding Pairs
The Birdlife project, launched a decade ago, focuses on increasing the number of breeding pairs. “To recreate the natural habitat of the European rollers – a humid environment with soft soils where these birds can uncover abundant food – we take water from drainage canals in neighboring lands and pump it onto the plot using solar pumps,” Lombardo said. The six-hectare area, provided by a local farmer, naturally collects water during heavy rains, making it demanding for cultivation.
“We are creating slight flooded areas, perfect for the European rollers and especially for the chicks,” the ornithologist added.
“If, one day, we manage to have 50 or 70 young European rollers survive here, we would already have almost half of all the chicks that could currently fly away in Switzerland.”
A significant challenge remained: foxes, which prey on eggs laid in ground nests. Previous temporary plastic barriers proved ineffective, with most nests being ravaged. This led to the installation of a permanent metal mesh fence, costing approximately 80,000 Swiss francs, funded by Birdlife and donors.
Lombardo dismissed the idea of the fence being a “prison,” stating, “The birds are, of course, completely free to approach and nest here when they return from their migration. But it seems the conditions suit them, as they are coming.”
Cattle Help the Effort
The barrier is positioned on a wide rubber strip to prevent frequent mowing and includes an external electric wire. Crucially, it features a tight mesh at the bottom to keep foxes out. At the top, “a second electric wire, already installed as a precaution, will be in place when raccoons arrive in the region,” Lombardo added.
On the inner side of the enclosure, a third electric line keeps Highland cattle at a distance. These cattle are intentionally allowed to graze on the land. “By trampling and digging the soil, they turn it over and expose worms and insects, which make up the food for the European rollers,” explained the biologist.
“Ideally, we would restore the waters of the Jura and let the Aar River meander in the Three Lakes region. This would restore all the marshy areas and it would be paradise for the European rollers. But that is completely utopian.”
Lombardo is confident the project can do more than just ensure the survival of this colony, one of the three largest in Switzerland, which currently hosts a total of 200 European roller breeding pairs. “If, one day, we manage to have 50 or 70 young European rollers survive here, we would already have almost half of all the chicks that could currently fly away in Switzerland. So yes, it has an impact!”
>. > See the report from Passe-moi les jumelles on the European roller:
An Artificial Intervention in an Anthropized World
The protective measures also symbolize a broader issue, as the fence represents an artificial intervention to help a wild bird. “In our world, the problem is that everything is becoming anthropized,” explained Raphaël Arlettaz, professor of conservation biology at the University of Bern. “Man is everywhere, modifying all ecosystems. The only solutions we can implement in systems where we continue to exploit are measures that have an artificial side. Of course, the ideal would be to restore the waters of the Jura and let the Aar River meander in the Three Lakes region. This would restore all the marshy areas and it would be paradise for the European rollers. But that is completely utopian.”
As an alternative to paradise, this European roller oasis is intended to serve as a model for other similar projects in Switzerland, as envisioned by Birdlife in a statement: “The goal is to quickly share proven knowledge and avoid unnecessary detours. Experiences carried out at the European level clearly show that isolated measures are not enough. Rewetting, surface size, habitat structure, grazing and protection must work in synergy. Where this succeeds, the chances of success increase considerably.”
Olivier Dessibourg
