News

Coypu and muskrat – a threat to biodiversity?

With the increasing spread of coypu and muskrat, their harmful effects become the focus of attention. Both species dig tunnels and burrows on embankments and feed on aquatic vegetation, damaging mainly reed plants like reed and bulrush. Reed vegetation constitutes the habitat of numerous animal species: birds such as the great bittern or the reed warbler breed here and migratory birds look for resting places on their transit in reeds. Different species of fish spawn in the reed beds, where juvenile fishes can find protection from predators thereafter. Furthermore, various insects, including many dragon- and damselflies, depend on reed plants.

Coypu and muskrat can massively damage reed vegetation through their burrowing and feeding activities and thereby compromise the habitat of numerous protected animal species.

A coypu feeding on the floating blade zone at Lake Dümmer

As part of the MICA project, the effects of coypu and muskrat on biodiversity are being investigated. For this purpose, mapping of aquatic vegetation, bird populations and dragonflies is carried out several times a year in the project areas and compared with data on the occurrence of coypu and muskrat (hunting statistics and camera trap monitoring).

Aschauteiche (German project area no. 2)
Abandoned channel of Vechte in Grafschaft Bentheim (German project area no. 3)
Lake Dümmer (German project area no. 1)

The Institute for Terrestrial and Aquatic Wildlife Research of the University of Veterinary Medicine Hannover and the Agricultural Chamber Lower Saxony carried out the first field mapping of the aquatic vegetation and dragonfly species in the German project areas in August and September this year.

Vegetation mapping at Lake Dümmer
Damselfly mapping at Aschauteiche
Dragonfly mapping at Aschauteiche

Kick-off “Alien Species – a discourse”

With increasing awareness of the society for the problem of invasive animal species, ethical issues concerning how to deal with these animals also come into focus.

The Institute for Terrestrial and Aquatic Wildlife Research participates in this dialogue with a public relations project that is funded by the Ministry of Science and Culture of Lower Saxony as part of the program Future Discourses. With the project title “Alien species – a Discourse: how do we deal with introduced species, and how do we want to deal with them in the future?” the issue of ethics has already being faced. The project aims to establish a dialogue between different interest groups and shed light on society´s attitude towards invasive species.

The kick-off event took place on September 24, 2020 at the University of Veterinary Medicine Hannover, in compliance with hygiene regulations in effect. Teachers and interested citizens were invited additionally to representatives from research, hunting, water associations, nature conservation organizations and politics. Partners from the German project areas of the Life-MICA project took part as well.

After short initial presentations, in which the opinion of the individual stakeholders were presented, there was an active discussion on various conflict topics, as for example: the conflict about the repartition of responsibilities between hunting and pest control, the problem of by-catches of protected species by trapping and the lack of awareness in the society for the threats imposed by invasive species. A further deepening of certain discussion contents and the development of a questionnaire will represent the next steps towards an impulse paper with which the project aims to raise a question mark. The topic of neozoa will be also made accessible to young people. For this purpose, a workshop box with exercises and illustrative material on the subject neozoa was prepared and will soon be worked on by students from different regions in Germany. Moreover, an informative short film on the subject of neozoa was made.

Additionally, you can find the recording of the event here.

Easier sampling with the improved autosampler

To discover the DNA of muskrats in the water, many samples have to be taken with the “autosampler”. Now a more compact and user-friendly version of this autosampler is available.

The autosampler is a device with the size of a large lunch box. It uses GPS to keep track of where it is. It takes a ‘sip’ of the water to be sampled every few meters. The device can be used in a boat, a canoe, on a quad or on foot.

Improvement

Mirjam Boonstra, Project Leader at the University of Amsterdam, is enthusiastic. “The university’s technical center has made this new version. We are very happy with it. The autosampler is now small and less heavy. It is a great improvement.”

Sampling routes

This summer there will be also experimented with making maps of the sampling routes. Boonstra: “We expect the results of this experiment this autumn. We will come back to that in the end of the year!”

Cooperation

The cooperation with the regional water authorities is going smoothly. “We cannot manage the muskrat trappers ourselves,” says Boonstra. “The regional water authorities are responsible therefor. We have contact persons there with whom we discuss the experiments. It is nice to receive feedback from them about how things can be improved. After all, they have the field experience.”

New phase

The eDNA project is now in a new phase where more extensive field testing is taking place. Boonstra: “It is important to know that what we have done in the pilot phase also works on a larger scale. That is a new phase. This good cooperation is therefore becoming even more important.”

Update from Vechte Area

In April, the first camera traps were set up on the Vechte’s canals and side arms in the Vechte area (project area 3).

At seven locations, day and night, they take pictures of all the animals that swim or pass by. In this way, we want to track down coypu and muskrat in the project area.

In the past months, hundreds of images have been taken and saved. So far, the photos have been evaluated manually: the animal species were identified and classified. In the course of the project, an image recognition software will be trained with the photos of coypu and muskrat. The software will then automatically recognize these animal species and will replace the time-consuming manual evaluation of the images in the future.

Here, we would like to present a selection of the most beautiful photos and the variety of the occurring species.

Sharpe your eyes, how many animal species can you recognize?

DNA Mapping: collecting samples in research areas

One of the components of the Life MICA program is DNA mapping. Here the migration routes of muskrats are visualized. The presence of muskrats has now been mapped until May.

This year, the current populations of Friesland and an area of 20 km around Friesland, including North Holland north, will be analyzed. In each atlas block (25 km2) we try to catch 3 muskrats: a male, female and juvenile. A genetic profile is made of all these muskrats. This profile is compared to the profile of the other muskrats. The aim is to establish the family relationships of the captured animals.

Collecting samples

Samples are now collected in the study areas. On this basis we can determine the migration and migration routes of the muskrats. Wageningen University will carry out these analyzes from February 2021.

Time schedule

The results of the study will be known at the end of 2021. With these results, smart camera traps will be set up along the migration routes in 2022 and 2023. Traps will be placed based on the observations made by these cameras.

Overview of the collected samples until April 2020

Field protocol for eDNA in use

In the research project eDNA, a field protocol for muskrat control has been drawn up.

  • The field protocol consists of five steps, beginning with yearly monitoring of all waterways, which are divided in 5 km routes (Step 1).
  • In the event that a route tests positive for muskrat eDNA, more accurate localisation is performed by sampling every 1 km and every 100 m (Step 2).
  • The eDNA results of Step 2 enable more accurate placement of the traps (Step 3).
  • After a (successful) catching period, sequential check-ups are performed surrounding each catch/eDNA location, in order to confirm muskrats are no longer present at the catch location and no expulsion took place (Step 4 and 5).

Free of muskrats

Should a sample still test positive, Steps 3-5 are repeated until muskrat eDNA is no longer detected. The area under investigation is then declared free of muskrats, and will be tested again during regular monitoring.

Civilian notification

Alternative starting point: In the event of civilian notification, the exterminator will investigate the location for the presence of muskrats. If traces are found, the field protocol is started at Step 2.

Download field protocol

Smart life trap for coypu nominated for award

Students of the HAS University of Applied Sciences in Den Bosch, The Netherlands, have designed and tested a smart life traps for beaver rats. The project has been nominated for the Green Education Impact Prize.

The smart life traps are equipped with a motion sensor, battery, modem and camera. The cage is linked to a database with photos of different animals. If the camera recognizes a coypu or muskrat, the trap closes. If the camera sees that it is another animal, the trap will not close. Animals like ducks, beavers and otters can then just get out again.

Further testing

The students tested the cage for 2 weeks in the area of the Rivierenland water board. One of the conclusions was that you need at least 100 photos of a species to be able to recognize the captured animal. The coypu was certainly well recognized. This year the water boards will further test the smart traps that the students have developed.

Award ceremony

In the project, the university college collaborated with, among others, the Rivierenland water board and the Union of Water Boards. The Green Education Impact Prize will be awarded on 13 February.

Why catch?

Muskrats and coypus traditionally do not belong in the Netherlands. They have arrived here due to human action and have no natural enemies. Muskrats and coypus dig in banks and flood defenses. This leads to security risks, economic damage and damage to biodiversity. That is why the fight against musk and beaver rats is necessary. The water boards employ nearly 400 specialized muskrat and coypu fighters. If they were not there, the population would increase rapidly.

Update 14 February 2020:

Unfortunately the students did not win. However, the water boards are continuing to develop this concept. In this video the students talk about their project.

The international kick-off of Life MICA

After more than a year of preparation, the kick-off meeting of the Life MICA project took place on 30 and 31 October 2019. An international collaboration with water boards, universities, nature institutes and regions from the Netherlands, Belgium and Germany, among others.

The Rivierenland Water Board was the host of the meeting, which was facilitated by Euroquality.

Aim of the project

The aim of this project: to innovate and work together to keep the population of muskrats and coypus in the research areas under control.

Getting acquainted

The first day was all about getting acquainted. Water Board Rivierenland kicked off with the general presentation about the Life MICA project, the goal and the strategy to achieve the set goals. The collaborating partners then introduced themselves and explained their contribution to the project.

Content

The second day the content of the project was discussed. Euroquality discussed the regulations from the Life program. What are the rules regarding financing, communication and project management? Subsequently, the actions from the Life MICA project were discussed and further steps were formulated.