Water vole

Water vole by Brett LewisWater vole by Brett Lewis

Arvicola terrestris

Famed as Ratty in Kenneth Grahame’s novel The Wind in the Willows the water vole was once a familiar waterside creature regularly seen in our rivers and ponds.

Their chubby whiskery faces, blunt noses and small ears readily distinguish them from the brown rat, which also inhabits waterways. They are almost wholly vegetarian, feeding on a wide range of plants, roots and tubers. They don’t hibernate but retreat underground where they store food but will emerge when the sun shines in the winter months. They need luxurious bankside vegetation, particularly grasses, rushes and sedges, to provide food and cover from predators and they also favour steep banks to allow them to excavate extensive burrow systems. In fenland situations they are known to burrow into tussock sedge which keeps them safely above fluctuating water levels.

Over the last twenty years the species suffered the most rapid and catastrophic decline in numbers of any British mammal and this was due to habitat loss and predation by the non-native American mink.

A national water vole survey carried out in the 1990’s revealed the devastating news that water vole was on the point of extinction in several counties. This galvanised the Trust into action and water vole conservation became a high priority. Between 2003-2005 we surveyed all Suffolk river catchments and the story was even more depressing – further dramatic decline on all rivers - in 2003 the river Alde had no water vole on its main channel!

However, the 2005 survey gave us hope indicating a healthy water vole population at key coastal sites and in 2007 there was great news regarding the Alde. Water vole site occupancy on the main channel had increased from 0% to 55%! In 2010 the picture was even brighter with water vole recovery in the River Blyth catchment the most successful of any catchment in Suffolk that has been re-surveyed in the last five years.

The Trust’s Water for Wildlife Project has been working for eight years to reverse the decline in water vole numbers by liaising with landowners to improve wetland habitat management, and by setting up a mink control project throughout all Suffolk’s rivers. By carrying out regular water vole surveys of our rivers, the Trust has established that where sustained mink control is carried out, water vole are successfully re-colonising our rivers, ponds and lakes and are now widespread and once again becoming a familiar and delightful sight along our riverbanks.