Conservationists join forces to save the vole

Wildlife at risk: Today we begin a weekly series featuring some of the animal and plant species covered by an ambitious rescue plan

Last week, the Government was set a tough challenge - to help fund rescue plans for 116 of Britain's most threatened or fast declining wildlife species, and for 14 rare types of habitat as well. The ambitious nature conservation scheme was drawn up by the Biodiversity Steering Group as a follow up to the 1992 Rio de Janeiro Earth Summit.

The group is a consortium of civil servants, representatives from government agencies such as the Forestry Commission and English Nature, academics and wildlife conservation groups. The Government has promised to respond to its plan next spring.

The water vole - Ratty in The Wind in the Willows - is on the biodiversity list because its numbers and range are in fairly rapid decline. It is a common little mammal with a population of about 1.2 million in the United Kingdom.

Larger than the field vole, it is a fine swimmer even though it lacks basic adaptations such as webbed feet and waterproof fur. It eats leaves, stems and roots above and below the water and lives for up to three years.

A national survey in 1989-90 failed to find signs of the riverbank-dwelling vole at 67 per cent of sites where they were previously recorded. The proposed goal for Arvicola terrestris is to halt the decline and then help the species spread back to its 1970 range by 2010.

Its habitat along canals and rivers is being damaged by erosion from boats and erosion repair work which heaps mounds of river-bed mud on the bankside, sealing its burrows.

Waterside development and the heavy human disturbance which comes from increased river recreation make life uncomfortable or impossible for the vole.

The mink, imported from North America and now breeding successfully in the wild, hunts it. Pollution of streams by pesticides used to control rats - rodenticides - is another cause of decline.

The prescription for recovery involves managing rivers, banks and the land nearby in a way which aids the water vole and curbing the use of pesticides.

Anyone who uses rodenticides illegally near where the voles are found should be prosecuted. Mink populations could be controlled by trapping in areas where voles live or to which they might return, although further research is needed to show whether this would be effective. The total cost of the programme is put at pounds 150,000 a year.