Water voles living at altitude on Beinn Eighe
Surprising altitude for water voles
Scottish water voles are genetically different from their English cousins. Photo credit Xavier Lambin University of Aberdeen
January 2012. The enigmatic water vole may be associated with our water and river systems but scientists have revealed it is it thriving almost 700 metres up a Scottish hill.Beinn Eighe National Nature Reserve
in Wester Ross, managed by Scottish Natural Heritage (SNH), is home to some of Britain's rarest wildlife, and a recent survey of water voles found the inhabitants quite happily defining territory at that altitude.
Peat is easy to burrow into
Water voles are chunky rodents up to 25 cm in length. They live along the edges of burns, rivers and ditches and feed on grasses and sedges while inhabiting burrow systems among waterside areas with lush vegetation. In upland areas such sites are typically in areas overlying deep peat which the voles can easily burrow into.
The water vole was once common throughout Britain and found fame as the character ‘Ratty' in the book ‘Wind in the Willows' but is now one of Britain's most threatened species. Its population has crashed by 94% over the past 50 years. However the Scottish Highlands are considered a stronghold for water voles, which are genetically distinct from their English and Welsh cousins and often have black, rather than brown, fur.
The survey was carried out last October by Highland-based consultants Waterside Ecology. Doctor Lorna Brown, who led the survey team, said: "We found signs of 19 different water vole colonies across the reserve, and it seems that the population on Beinn Eighe is in good health. "One colony was living in a small patch of grassland the size of a dining table nearly seven hundred metres up the mountain. The voles would have had to travel hundreds of metres over rocky terrain to search this out.
"These tiny colonies might just consist of one female and her offspring, and adults rarely survive to breed two years in a row, so it is vital for the voles to move around to find mates and recolonise these scraps of good habitat."
The main threat to water voles has been the spread of non-native American mink, a voracious predator which can wipe the voles out over whole river catchments. Peter Duncan of SNH is pleased that so far there are no signs of mink establishing on the reserve, but highlights the need to remain vigilant.
He said: "We have been setting live traps to monitor for the presence of mink along with other estates in the area to support the Scottish Mink Initiative which is running just north of here. Wildlife and angling are important in rural economies like Wester Ross. This survey is really useful in terms of planning our management on Beinn Eighe, as it locates all the water vole colonies. We can make sure that the lush grassy areas by watercourses which the voles need do not get overgrazed or shaded out by regenerating woodland."