FEARS that a vital water vole colony in Dorchester has been wiped out by last year's flooding have prompted an urgent call for volunteers to track down any survivors.

Meadows around the River Frome are thought to be one of the most important sites for the endangered species and nature-lovers are combing the area for any signs of them.

These include Brian and Christina Ridsdale, from Bradford Peverell, who say they have only seen three water voles this year - and fear this could be the same animal seen at different times.

The retired couple, who are members of the Dorset Wildlife Trust, are urging people to report back if they spot a water vole, which was made famous as the mis-named character Ratty in Kenneth Grahame's The Wind in the Willows.

Brian said: "Has anyone seen Ratty?

"We are privileged to have in the river meadows of the Frome one of the most important colony of water voles - or rather, we did last year.

"I fear that the winter floods have wiped them out. Water voles have lost 90 per cent of their numbers in a decade and they are vulnerable to floods."

Christina added: "It is particularly important in light of last year's flooding. We are concerned about them."

Bronwen Bruce, Dorset Wildlife Trust's river and wetlands conservation officer, said: "Water voles are an endangered species and their numbers are declining massively.

"We were concerned that last winter's floods would have affected them, particularly around the River Frome above Dorchester, which is actually the site for one of the largest water vole populations in the country.

"We thought they might have been washed out so we are actually carrying out a survey to see whether that is the case. A survey was carried out five years ago, but since the flooding, it seemed important to do it again."

The survey was started in July this year and is likely to continue into 2002.

Bronwen, together with a group of volunteers, looks for and records signs that water voles have been in the area. These include their burrows, droppings and signs that the vegetation they eat has been disturbed.

If you have seen water voles or would like to help the Dorset Wildlife Trust, please call Bronwen on (01305) 264620.