More Beavers in the Canton of Zurich

The beaver continues to spread throughout the Canton of Zurich, as the latest survey shows.

The once-extinct rodent has already densely populated the northern part of the canton. In recent years, it has also established itself in new territories in the south of the canton.

Since its reintroduction in the second half of the last century, the beaver has been gradually spreading once again along the waterways it once inhabited — including in the Canton of Zurich. In particular in the northern part of the canton, both individual animals and beaver families have been continually settling in new stretches of water. Every three years, the Fisheries and Hunting Administration of the Canton of Zurich conducts a survey to determine where and in what numbers wildlife has settled in the canton. Between November 2019 and March 2020, 70 volunteers set out to track down signs of their presence. As the beaver continues to expand its range, this time not only the relevant stretches of water were surveyed, but for the first time the entire approximately 1,000 kilometres of waterways in the canton were walked.

29 New Territories Recorded

As evidenced by various traces such as feeding and felling sites or lodges, around 480 beavers now live in the Canton of Zurich, distributed across 135 territories. The beaver population has thus increased by 21.5 percent over the past three years, and the number of territories by 27.3 percent. The current distribution of the beaver in the Canton of Zurich remains concentrated — as in the previous survey — in the northern half of the canton. Here, the beaver inhabits primarily the Thur and the Rhine rivers and their respective catchment areas. The increase in the beaver population is, however, mainly due to the ongoing recolonisation of the southern part of the canton. In the process, various individual or pair territories have also developed into family territories.

The Beaver Moves Southward

The strongest population increase since 2017 occurred in the Glatt area (including Greifensee), with ten new territories occupied by 15 individuals. Most abandoned territories were observed primarily in the Thur catchment area. Although six new territories were found in this area, five territories were also abandoned. Among the waterways surveyed for the first time, territories were identified along the Reppisch and at Lake Zurich.

«Architect of Nature» creates species-rich habitats

Wherever the beaver settles, it actively shapes the landscape as a busy «architect of nature.» It creates unusually species-rich habitats, making it a welcome ally in the return of rare plants and wildlife, such as the kingfisher, the midwife toad, the grass snake, wading birds, and rails. Fish also become more plentiful in waters inhabited by beavers.

To create transport routes and access food, beavers fell trees, dam streams, and sometimes undermine roads and paths. This can lead to conflicts. In such cases, the Canton of Zurich's beaver advisory office helps to keep the beaver in check and prevent damage.