OTTERS and water voles seeking to make a comeback in the Swindon area have found an unlikely ally the Highways Agency.

Both species are doing well in South Gloucestershire and the area around the Severn Estuary. And the Highways Agency is to investigate helping them move further afield by making its roads less of an obstacle.

The Agency is responsible for major trunk roads such as the A419 and the M4.

If necessary it can make them more otter-friendly by providing runs in drainage culverts which go under the roads. These have already been put in place in Devon.

The Agency can provide help for water voles by ensuring roadside ditches have sufficient vegetation to provide food and habitat.

Spokesman Robin Miller said: "Studies have shown that otters and water vole colonies around the Severn are growing and recolonising further inland. We are studying roads in the Swindon area to ensure that they are not causing any hindrance to that re-colonisation.

"Since otters were last known in this area some substantial roads have been built. We just want to make sure they aren't going to make a substantial barrier to their continued re-introduction."

Otters and water voles both suffered a dramatic decline since the 1950s. Otters were almost wiped out because of agricultural pesticides, hunting and loss of habitat.

But otters in particular have been making a comeback in recent years, helped by the banning of most harmful pesticides, improvement of habitats and reintroduction schemes.

The water vole is also known as the water rat, or Ratty in Kenneth Grahame's book the Wind in the Willows.

The Highways Agency owns some 30,000 hectares of land an area roughly the size of the Isle of Wight. It intends to spend £15 million over the next 10 years on what it calls a Biodiversity Action Plan.

This includes creating hundreds of new wetland features for wildlife, 100km of hedges and installing 1,000 bat roosting boxes.