Reintroduction of the European Bison in the Solothurn Jura

Since 2019, the Vontobel Foundation has been supporting the scientifically grounded project “Wisent Thal,” or “Bison Dale,” which is testing whether the European bison, an endangered species, can be successfully reintroduced in Switzerland. The project aims to see if, after approximately ten years, the test herd can be released into the wild with the status of a protected species.

The European bison is a large bovine ruminant native to Europe. A herbivore, it subsists entirely on a vegetarian diet, eating grass, herbs, leaves, and tree bark. Adult bison require roughly 30 to 60 kilograms of food per day. These animals are gentle, peaceful animals that move in herds.

The Wisent im Thal Association was founded in 2017 with the goal of reintroducing the European bison to the Jura Mountains near the town of Solothurn. Since 2022, a small free-ranging test herd, well-monitored and managed and currently consisting of ten animals, has been followed to assess whether the bison—otherwise extinct in Switzerland since around 1,000 years ago—can once again thrive as wild animals in the Jura.

The accompanying scientific research examines the animals’ dietary choices and the herd’s behavior toward humans, other livestock, and different kinds of facilities. Any damage to their surroundings or additional costs are systematically documented with compensation being paid to the people affected.

Another objective of the project is to familiarize the local population with this largely unknown species. A bison ranger is available to provide information, advice, and assistance to individuals who come into contact with—or conflict with—the bison, ensuring prompt on-site support.

If, after approximately ten years, the test phases yield positive results, the test herd can be formally released into the wild. This means that the bison will receive the legal status of a protected species, entrusting their care to the state.