NATURALISTS near Darlington have made a remarkable discovery which offers hope for one of the country's most endangered animals.

They have found one of the North-East strongest colonies of water voles - a creature predicted to become extinct in Britain by 2006.

The find was made at The Whinnies, a Darlington Borough Council nature reserve at Middleton St George, which is maintained with support from the Middleton St George Wildlife Group, Durham Wildlife Trust, and the British Trust for Conservation Volunteers.

Charlie Chapel, chairman of the wildlife group, which is part of Durham Wildlife Trust, said signs of voles were discovered almost all the way around a pond on the site.

He said: "We always knew we had water voles in the area because they are in Goosepool Beck, which runs through the reserve, but we did not know that we had so many.

"Water voles are as endangered, if not more so, than the red squirrel, so this find is fantastic. It is one of the most important sites for them in County Durham, if not further afield."

Improvement work is now planned at the pond, which is used to take run-off water from the nearby Middleton St George bypass.

Helen Tomb, project officer for the British Trust for Conservation Volunteers, said: "This is one of the area's main sites for water vole and we intend to keep it that way."

Water voles are under pressure because of attacks by mink and loss of habitat to development, overgrazing and dredging. The animals have been declining for a century, but particularly over the past 20 years, with numbers now down 90 per cent.

Stuart Priestley, wetlands project officer for Durham Wildlife Trust, who visited the pond with members of Middleton St George Wildlife Group, said: "Any new find of water voles is good news because the populations have become so separated."

Council countryside officer Sarah Storey said: "This is a tribute to partnership working, because so many people are involved in looking after the pond. We knew we had water voles but we did not know they were there in such numbers. It is fantastic."

Darlington is already a regional stronghold for the creatures, which exist at the Drinkfield Marsh nature reserve, the restored section of the River Skerne off Haughton Road, and along the borough's becks.