The water vole makes its home on river banks

Of the 36 sites revisited 61% showed signs of water voles - more than double that of a 1996 survey.

Other areas of the country, such as East Anglia and the South East now have reasonably healthy water vole populations.

However, the news is not as optimistic for elsewhere in the South West.

Cornwall Wildlife Trust has just finished a reedbed survey for water voles - but none have yet been found.

Beth Nightingale, rivers and wetlands officer for the Devon Wildlife Trust, said that an appeal last autumn for sightings of the mammal in the county had yielded no results.

'Enigmatic mammal'

"The survey will restart in the spring, when the chances of finding reliable signs of water voles are better.

"We still need to find any remaining populations of this attractive and enigmatic waterside mammal which was once relatively common in Devon, so they can be protected and safeguarded for the future."

Bronwen Bruce, rivers and wetlands officer for the Dorset Wildlife Trust, said it was thanks to Dorset's habitat that Ratty's numbers had increased.

"In Dorset, there's a lot more open streams with full vegetation. But even with the numbers we found, they still have not reached the numbers they did historically.

"People can make sure they don't mow to the edge of the river and leave a fringe of vegetation by the water.

"If they have rivers in their village, keep and eye on it and contact us or the environment agency with any queries."

Photos courtesy of Martin Senior/Wildfowl and Wetlands Trust