For the sake of our water voles, erase the alien invaders
I WAS just wondering what to write about this week when a reader’s question fluttered into my in box concerning the lack of water voles on his patch over the past number of years. I could simply say ‘American mink’, but I will say more.
This adaptable, opportunist and indiscriminate hunter is credited with having wiped out 90 per cent of water voles and has now colonised virtually the whole of the UK after escaping from fur farms at various times during the last century. Some managed to escape when mink coats went out of fashion and fur-farms were neglected, and still more gained access to our countryside when their keepers were called up to fight for the British Army. Latterly, many were deliberately released by animal rights activists.
Thirty years ago I discovered their droppings high in the Peak District Hills, at 700 feet above sea level, on the banks of a small stream near my Bleak House home. I also found feathers, scales and fur. In other words, they were preying on brown trout, small birds and mammals, including the scarce water vole. They may even have some impact on cuckoos which use the nests of ground-nesting birds to lay their eggs in.
Being semi-nomadic, mink go where their food is. I was hoping that they would soon clear off, but no such luck - they killed my chickens in broad daylight.
Of course, I have nothing personal against mink, it’s a great survivor, but I would like to see the back of it. Teams of pest-controllers need to be employed across the country if anything is to be done about the mink.
In the early eighties, another alien was completely eradicated from Norfolk and East Anglia, the giant coypu.
The animal’s habit of undermining the counties dykes and riverbanks ensured an early exit from these shores.
Most ‘incomers’ or non-native species cause no problems for native flora and fauna, but others such as the Japanese knotweed, from Japan, are particularly troublesome.
Japanese knotweed is perhaps the most invasive plant in the world, and was a massive problem for the 2012 Olympic Delivery Authority to overcome, because although only found on a small percentage of the total area of the site to be developed, there was no easy way to get rid of it and they were not completely successful.
Not many people know this but they spent millions dressing the area with herbicide, before cutting back large stems.
So powerful is the Knotweed its roots can penetrate several metres through concrete, and even if buried deep below the ground in landfill sites it can grow again after laying dormant for many years.
The species also causes problems in terms of flood management, increasing the risk of riverbank erosion when the dense growth of the plant dies back in the autumn exposing bare soil. It can also create a flooding hazard if the dead stems are washed into the streams and clog up the channel. A fragment of root as small as 0.8 grams can grow to form a new plant.
The plant, brought to England and planted by the Victorians, is now on the government hit list, but he cost of a national eradication programme using current techniques is prohibitively expensive.
However, the Environment Agency does take local measures if flood defences are compromised.
The Japanese knotweed is just one of many alien species to have found its way to these shores. In whatever manner that they managed to get here, some have caused untold damage to our native flora and fauna, and if I could press a button now, and they would vanish from these shores forever.
Consider it pressed.