Wildlife observation: On the trail of weasels with high-tech photo trap
Wildlife observation with a difference: ZHAW engineers have developed a new type of tube photo trap for small mammals. This allows endangered species such as weasels to be better recorded - with the help of non-professionals. Until now, this was extremely time-consuming and only possible on a selective basis.
Wildlife observation still plays an important role in Switzerland. The habitat of Swiss weasel species such as ermine or mouse weasel is becoming smaller and smaller. Therefore it is urgently necessary - besides protection and promotion - to record the existing populations. This is the only way to detect negative trends at an early stage or to review promotion measures.
Until now, however, it has been extremely difficult to detect small mammals and therefore only possible at certain points. For this reason, ZHAW researchers led by Nils Ratnaweera have developed a new type of photo trap that should simplify the detection of endangered wild animals. The advantage over conventional detection methods is that the new TubeCam requires little maintenance and automatically uploads images to the Internet. There, private individuals can help with the time-consuming sorting of the images - in keeping with the spirit of Citizen Science.
Autonomous system
Photo trap consists of a tunnel, which is T-shaped and made of plastic. In one arm of the tunnel there is a heat sensor, a camera and a small computer, all packed waterproof. When an animal comes through the tube, the sensor registers the temperature rise, the camera shoots a series of photos, and the processor automatically uploads them to the Internet via cell phone network.
"During our research, we discovered that numerous other animals live on the Zimmerberg, such as hedgehogs, insects, amphibians," explains Nils Ratnaweera. The new trap is said to be low-maintenance, easy to use and evaluable without much expertise. "You only need to place the TubeCam and switch it on, everything else runs automatically," explains the researcher.
With conventional photo traps, the nimble and small animals can hardly be caught. The advantage of the new method is that the naturally curious weasels want to explore the tunnel and can be captured there sooner than with a conventional photo trap. Classic track tunnels, which record animal tracks using ink, also have their disadvantages.
The special ink used is relatively expensive to produce, and the paper has to be changed every seven days. Above all, however, experts are needed to evaluate the traces.
Citizen Science
Typically, a TubeCam takes thousands of pictures in a few days and only a few of them really show a weasel. That's why the project relies on the cooperation of private volunteers who evaluate images. "Right from the start, we wanted to develop a method that would allow us to involve laypeople," explains Nils Ratnaweera.
The idea for TubeCam came from Nils Ratnaweera, and the funding came from the Institute of Environment and Natural Resources of the ZHAW Department of Life Sciences and Facility Management. However, engineers from the ZHAW School of Engineering are also involved. At the moment, only a few prototypes of the TubeCam exist. Before a small series can be produced for the first time in 2018 as planned, an electrical engineering master's student will be reworking the hardware starting in the fall. The team is also still looking for an investor.
Currently, the test phase is still running; next year, the website should be fully operational. The ZHAW people are also researching automated image evaluation.
Promotion just as important
But the ZHAW researchers not only want to record weasels, they also want to protect them. As part of the "Weasel & Co am Zimmerberg" project, numerous piles of branches and stones are being created and barns are being prepared as winter quarters. Farmers are compensated financially for this. Weasels are friendly animals, and as mouse eaters they are also well received by farmers. In their wake, many other species can benefit: "Stoats have high demands on the size of the branch pile - that's why we always build them at least three by three meters, with a height of one and a half meters," says Nils Ratnaweera ZHAW researcher.
Interested people have the opportunity to view the approximate locations of all TubeCams and their images on an entertaining site, virtually in real time. Those who want to help with the classification can do so after a simple registration:
