Weasels are carnivores and depend on sufficient prey populations to survive. Their main food source are voles, which live mainly on meadows, pastures and fallow land. These habitats are coming under more and more intensive use, resulting in weasels losing their most valuable hunting grounds. In addition, as fields grow ever larger, they often lack the structures they need to protect themselves from their enemies, such as birds of prey. This led to a noticeable decline in weasels in many areas of Switzerland.
In this project, we want to find out where weasels occur in the Swiss Midlands. We are also interested in whether the species composition of the prey differs between locations and whether this has an influence on the occurrence of weasels.
Since observations of weasels are rare and difficult to plan, other indirect methods must be used to detect weasels. In this project, we use wildlife cameras, which take a picture or record a short video when something is moving in front of it. By placing the wildlife camera inside a box, we increase the chance of capturing weasels. We use the tendency of the weasels to explore holes and openings for possible prey to trick them into searching our boxes and being seen by our cameras. The animals usually remain in the box for a moment, which makes it easier to film these agile animals. In addition, with this setup we greatly reduce the chance that a moving plant or person will falsely trigger our camera. Besides weasels, other wild animals also visit the boxes. For example, grass snakes, voles, polecats and birds.
As predators, weasels are at the top of the food chain and are indicators of the state of an ecosystem. If the number of weasels declines, this is an indication that the number of prey animals, in this case voles, are also declining. However, the latter are an important food source for a large number of other animals.
While the stoat, a major species in the weasel group, is still fairly common in Switzerland, the second species, the least weasel, is listed as vulnerable on Switzerland's Red List of Endangered Species. This means that this species is at high risk of extinction in nature in the immediate future.
Long-term monitoring of weasels and their prey populations is therefore very important for nature conservation. However, such monitoring is very costly and often only possible with the support of many volunteers spending many hours in the field. Even then, the analyses of the videos would have taken us months of long work. But with the help of you citizen scientists, this camera trap data can be analyzed at your leisure from the comfort of your own home. Thank you for helping out with this project!
In the course of the year we have made innumerable videos of the animals visiting these camera trap boxes at different locations. Alone we will never be able to look through them all. Therefore we are dependent on your help. Help us find out who is visiting the boxes.
On the observation platform wildenachbarn.ch sightings of stoats and least weasels are collected. These observations will flow into conservation projects as a data basis.
The project is supported by: