The Dutch have to be the world's experts on claiming land from water. People say that "God created earth, but the Dutch created The Netherlands!" A large part of the country is polderland. That means that former swamps and lakes have been reclaimed and are kept dry by drainage. A polder is created by making a ring dike around a swamp or lake. This dike, in turn, is surrounded by a drainage canal. The water from the area which is to be reclaimed is pumped in to that drainage canal and finally discharged to the sea. These artificial drainage canals are at a higher elevation than the inner polderland. Obviously, for this form of land development, a complex system of ditches and canals is necessary. Polders are at risk from flooding at all times and care must be taken to protect the dikes surrounding them. Some animals dig tunnels in dike and canal walls, undermining their structural integrity; the Muskrat (Ondatra zibethicus) is notorious for this behaviour. For this reason in The Netherlands it is actively hunted to extinction. Because the Government in The Netherlands still objects to the use of rodenticides in the aquatic environment where Muskrats live, control is still carried out the good old fashioned way by means of traps and nets. Because these kinds of catching methods are used, the Dutch prefer to have it done by persons who are trained to do this work as their daily task in Government Service. I don't know if I qualified for that, but was still keen to give it a crack.
Andreas and I in our canoe on the trail of some pesky Muskrats
Early on Friday morning Andreas (an old friend of Linda's) picked me up from Zuiderland 8 and took me to "Muskrat HQ." We loaded up the back of the Citroen 4x4 Econovan (what the?) with traps and hooked on the boat trailer. After a short drive and with some adept manoeuvring, Andreas dropped the converted airboat in to a shallow canal and threw in all the necessary paraphernalia for Muskrat hunting. Ominously, we both suited up in chest high waders and shoulder length rubber gloves. Blasting through the canals with the 15hp outboard was a thrill, but there was a serious issue at hand. The holes made by Muskrats in waterways interfere with drainage, particularly in the often century-old smaller polder dikes, which are found in the most densely populated areas of The Netherlands. Large residential areas, airports, and other important centres may be inundated following the failure of one of these dikes.
Pulling the boat up at a stand of reeds, I was ordered out of the boat and in to the waist deep brown sticky 'water' of the canal. Following Andreas deeper in to the reed bed we discovered some fresh signs that Muskrats had been eating the plants there. "Now I know they are living here" Andreas said. With the presence of Muskrats likely there was a new urgency about our mission to find their 'building' and lay our traps. After struggling back to the boat and hauling myself in, coated in foul smelling mud, the outboard was slammed in to reverse and we were off. At every likely hidey hole we would jump out of the boat and search for Muskrat burrows. The entrances are always underwater, so searching involved walking along the edge of the canals sticking your feet and hands in to the bank to feel for their 'pipes', as Andreas calls them. We found 2 'buildings' that day, and 12 pipes giving the Muskrats entry and exit below the waterline.
Setting snap traps in underwater Muskrat burrow entrances
In order to give yourself the best possible chance of catching a Muskrat as it enters or exits its lair, you need to 1 - make sure you put a trap in every burrow, and 2 - modify the round burrow entrance to accommodate the square trap. You also must be careful not to snap your fingers off in the trap as you are positioning it just right ... oh and not forget to mark it with a flag so you can find it again. After a day blatting around the canals, right past peoples homes and businesses, under bridges and through tunnel construction sites - all the time remembering to think like a Muskrat - I was shattered. I was none the less excited at the prospect of catching my first Muskrat, and the next day I wouldn't be disappointed.
A Muskrat - its head firmly gripped by the snap trap At a more reasonable hour on Saturday morning Andreas and I set off to check the traps we had set the day before. Instead of the stable and relatively comfortable boat from yesterday, we unleashed the stealth of a (one man) canoe. It was precariously unstable once I wedged my ass in to the front, and the bow rested only 7 or 8cm above the water. After waiting for a gap in the boat traffic on a main canal, to avoid any bow waves which would have undoubtedly capsized us, we managed to stay upright as we retraced our steps to check the traps. I know there is something weird about getting excited to find a dead waterlogged rat in a trap, but hey I'm a science nerd. Adreas keeps rats in his freezer. Turns out we caught two of the little critters, and in doing so did my part in protecting the polderlands of The Netherlands. You can thank me later.
Saving Amsterdam one Muskrat at a time Despite having an amateur like me on board, Andreas and his team have, since beginning operations in the 1940's significantly slowed the spread of Muskrats. In general, only 25% of the animals reach their first reproduction period; and there is continuous inspection of the places where muskrats occur, which make it possible to take rapid action when damage occurs or is impending. You have an awesome job Andreas - you are The Muskrat Hunter. Thanks for taking me along and showing me a very unexpected side of The Netherlands's polderlands!