THE otter has continued its recovery from the brink of extinction by moving into urban areas for the first time in three decades, according to a report published today.

Researchers for The Wildlife Trust discovered the animals using waterways in more than 100 towns and cities, including Durham, Sunderland, Newcastle, Teesside, particularly Middlesbrough, York and Boroughbridge, in North Yorkshire.

The organisation says otters are now regular users of major urban waterways and although, in many cases, they were passing through, in Newcastle they are resident. There have even been reports of cubs in the shadow of the Tyne Bridge.

Otters nearly died out in the 1950s because of highly toxic agricultural pesticides, deteriorating water quality in rivers, and the loss of riverbank habitats to drainage and flood defence works.

Water quality has improved in recent years, increasing fish prey for otters, and rural populations have been expanding.

Northumberland animals, for instance, have headed south to re-colonise the main County Durham rivers.

However, it is only recently that they have been reported in urban areas and Dr Simon Lyster, director general of The Wildlife Trusts, said: "The recovery of the otter is the most exciting success story of the last decade and is a tribute to volunteers and professionals that have worked so hard to make this recovery possible.

"Watching otters at play has largely been restricted to remote areas of countryside, but now otters seem set to become a part of urban wildlife, too."

Brian Lavelle, Yorkshire Wildlife Trust's Water For Wildlife officer, said: "Whilst this appears to be good news there is no room for complacency. Otters still suffer from a lack of good riverbank habitat due to building development, pollution and death through road accident."

The Wildlife Trusts appealed to urban developers and planning authorities to take account of otters and incorporate road underpasses and otter-friendly bridge ledges into their projects.