As you probably know, because I go on about it quite a lot, I have a lake at my house in France. It’s probably more of a pond than a lake but let’s not quibble. It is beautiful, but overly weedy and plagued by large rodents called coypu (in English) or ragondin (in French).
They are a South American species, similar to the musk-rat, brought over to Europe for their fur and then accidentally released into the wild. They love France! They have no natural predators and in my bit of France there is a lake or reservoir around every corner.
They eat grass, reeds and roots; consuming about one-quarter of their body weight every day. They grow to between 5kg and 10kg so are one of the largest species of rodent. They are sexually mature within 3 to 4 months and can produce up to three litters of pups per year. Fortunately they don’t often live beyond 3 to 4 years in the wild.
They are fantastic diggers and burrow into the banks of lakes and rivers, often causing a huge amount of damage. They have completely under-dug the far bank of my pond and caused three trees to fall into the water. They are a menace!
I think they are quite attractive creatures and I find it rather thrilling to sit next to them on the bank, but I desperately want to be rid of them. They are a serious pest in France and are often trapped in cages or shot by exterminators. I have trapped a few but am really looking to make my pond less ragondin friendly so that I don’t attract new ones, once the current occupiers have been removed. When they escaped into British waterways between the Wars, they caused a lot of damage. A government backed campaign eventually removed them (the last one was killed in 1989) and we are officially clear of them in the UK.
They apparently make very good pâté, which is low in cholesterol. They have not really caught on as a healthy eating alternative in France despite attempts to sell it to those crazy English types!
Rat sandwich anyone?
Questions…
- Why do the fish depend upon the weed growing in my pond (apart from as a source of food)?
- What trophic level do the ragondin occupy?
- Why do ragondin need to eat so much to maintain their levels of activity?
- What two functions do the roots of trees perform?
- To what food group does cholesterol belong and why is it potentially harmful to health?
- Ragondin are typical mammals. What features define an animal as being a mammal?
- Why are invasive species such as ragondin (or Japanese Knotweed) often so much more damaging to an ecosystem than native species?
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