‘Curious what I’ll find in the clamps tomorrow’

Around 8 am, muskrat fighter Tjitse Kuipers (43) sends his aluminum boat into the smooth water of the Steenbanktocht, into the Noordoostpolder. In the reeds on the left bank of the narrow ditch, the song of a bluethroat breaks the silence. A reed warbler flies up from the sugar beet field on the right.

Kuipers, in a green waders, his sunglasses full of mud splashes, constantly peers at the water, which gently laps against the banks of the trip. His eyes flash along the reeds. In some places the stems do not stand proudly, but they lean sadly over the water. “We have to be careful here,” he says. When the boat passes large, loose clumps of reeds, Kuipers turns the engine off and maneuvers the snub nose to the side. He grabs a pair of armpit-length green gloves from the bow, swings both legs over the edge and steps into the water. “Yeah,” he says triumphantly, fishing a reed out of the murky water. ‘Cut off: a muskrat has been at work here.’

Lightning fast reproduction

The story goes that in the early 20th century a Czech count brought six muskrats from North America for their precious fur. Five made it to Europe alive. What the count was not aware of is that muskrats reproduce at lightning speed. A female, the nut, can give birth to a nest of an average of five to eight young three times a year. In the same year, the muskrat pups from the first litter are old enough to reproduce. By the time the Czech count realized it was time to shoot the beasts, there were already millions of them.

Muskrats pose a danger to the dikes and banks. The brown rodent, which can grow to a length of 40 centimeters, digs away a cubic meter of sand in one year. That is more than twelve wheelbarrows full. Multiply that by the tens of thousands of muskrats that swim around in the Netherlands and the animal poses a threat to a country below sea level. In addition, the animal disrupts biodiversity by gnawing away riverside vegetation – which is also a breeding ground for other animals. In the Netherlands, the muskrat has hardly any natural enemies. That is why the Union of Water Boards decided in 2019 to push back the invasive exotic species to the national borders.

To do this job on behalf of the Zuiderzeeland Water Board, Kuipers sails every day with his dog Floris, a white-brown heath guard, across the ditches between the polders to catch muskrats. In 2021, he and his colleagues caught more than three thousand specimens. In the whole of the Netherlands there were about 45 thousand. The amount of captive muskrats in the Netherlands decreases every year. According to Kuipers, this means that the muskrat catchers are doing their job well. In Friesland, the fighters have even almost won the battle against the muskrat: in 2021 they only found two hundred rats in their clamps.

Bycatch

The animals dig holes in the bank with the entrance just under the water, says Kuipers, standing in the water up to his thighs. ‘A water lock, super smart’. With his foot he feels the blubber around the gnawed reeds, until the tip of his boot disappears into a hole. He digs into the hole with his gloved hand and holds up a handful of mud. Blades of grass stick out of the brown gunk. ‘Bite’, says Kuipers. ‘Nuts with young have to eat a lot of grass to get the milk production going. This is a build with boy.’ He lifts his backpack with clamps from the boat and puts an iron clamp for all the corridors that he finds with the help of his dog Floris. They are powerful clamps: if a rat walks into them, the animal is killed instantly. Kuipers: ‘Yesterday my hand was still in between. That leaves you with a bad bruise.’

Sometimes pest control agents also find bycatch in the clamps. The animal ambulance has examples of entangled swans, cormorants and herons. This is partly why the Animal Protection is against the eradication of the muskrat, says spokesman Niels Kalkman. ‘Moreover, the aim of the Union of Water Boards to reach a zero level by 2034 is unrealistic. Animals do not adhere to the national borders set by us. Unoccupied living space will sooner or later be occupied by muskrats, from within or outside the Netherlands.’

Animal-friendly catching

However, it is not an option to let the animals swim, says invasion biologist Rob Leuven of Radboud University. ‘If you do nothing, the population will develop explosively for years. Safety against flooding and negative effects on biodiversity outweigh animal welfare.’ He advocates animal-friendly catching. For example, experiments are underway with smart traps, which only close when a muskrat or coypu walks in. The Union of Water Boards is also committed to the search for DNA traces of the animals in water samples. This determines whether there are muskrats in the area and where they are, so that fighters can catch more effectively.

Kuipers comes from a real catcher family. His father caught moles, as did his grandfather and great-grandfather. Still, muskrat catcher is not his dream job. If his wife hadn’t vetoed her, he would now be in a log cabin in Canada as a forest manager. “But muskrat fighter comes closest. Look how beautiful it is here’, he says, gesturing to the sunny polder. “When I sit in front of the TV tonight, I’m already curious what I’ll find in the clamps tomorrow.” He finds it anything but contradictory that a nature lover like him kills animals every day. ‘I am part of nature. Bigger animals kill the smaller ones. If I ever end up in that Canadian forest again, I might be devoured by a cougar. Then the circle is complete.’