A walk around some ornamental lakes near our home produced a nice surprise when we spotted something small and brown swimming among the coots, mallard and swans. At first it was difficult to identify the visitor but we quickly realised another two were swimming nearby. They were water voles, lovely harmless little creatures that are often mistaken for rats. Indeed, Ratty is one of the characters in Kenneth Grahame’s famous book "Wind in the Willows" but in fact he is a water vole. In some ways, it is a shame that he is erroneously described in this way because generations of readers now refer to these creatures as water rats. They are not rats – they are voles.
Rats can swim and often live beside urban rivers and lakes, but they can tolerate polluted water, whilst the voles need very clean water in relatively quiet and undisturbed areas. Voles live on the banks of lakes, ponds, slow-moving streams and smooth rivers with the entrance to their burrows sometimes being beneath the surface of the water.
It is never easy to distinguish a swimming water vole from a brown rat but the vole is rather plumper with a chubby rounded face and tiny ears that are almost hidden among its thick fur. One problem is that both animals are about the same size and colour, ie: about eight inches long (20cm) with dark brown fur, and both are excellent swimmers. Voles, however, have a shorter tail but this is not always evident when they are swimming. Their diet consists almost entirely of water-side plants.
They can be very active during the day but dislike being disturbed by noise, people and water-born craft, preferring to spend their lives peacefully near the water and rarely venturing far from their home patch. They may be tempted to move if their home area becomes too overcrowded, or if the water becomes the haunt of tourists and their boats. A drop in the level of the water will also persuade them to find another home.
Sadly there is evidence that water voles are one of the most rapidly declining mammals in the UK. A national survey in 1989-90 failed to find signs of voles in 67% of sites where they were previously recorded. This was thought to be due to modern methods of controlling waterside vegetation, insensitive management of riverbeds and bankside reinforcement and predation by mink. As the lower reaches of rivers become unsuitable for habitation, the distribution of water voles becomes discontinuous and existing sites become isolated and vulnerable.
Fortunately there are now several schemes being put in place by wildlife conservation bodies to reverse this decline and, as water voles repond quickly to habitat improvement, there is a good chance that in time their numbers will increase.
Posted by Peter N. Walker @ 09:38 AM GMT [Link]