THE water vole is the UK's fastest declining mammal - mainly because it is often mistaken for a rat.

Pest controllers, builders and the public often poison them or disturb their homes because they think they are rats.

But an initiative launched by the Wildlife Trusts aims to help people spot the difference. It says that water voles have disappeared from almost 90pc of the sites they occupied in the UK in the last 60 years owing to the loss of their riverbank homes and being preyed upon by the non-native American mink.

Brian Lavelle, of the Yorkshire Wildlife Trust, said they were tirelessly working to restore the vole's riverbank homes and to stop indiscriminate poisoning.

"Air rifles are also a major problem. Many people mistake them for rats and shoot them," he said. "Identification is the key to overcoming the problem. Rats have prominent ears and a hairless tail but water voles have hidden ears and short, furry tails. They are an endangered species and we ask everyone to play a part in protecting them. Water vole discoveries can be reported to the Yorkshire Wildlife Trust."

The campaign involves sending descriptions to pest control professionals and developers and issuing guidelines for the public.

The Yorkshire Wildlife Trust, alongside other conservation groups, is also pushing for full legal protection for the water vole under the Wildlife and Countryside Act 1981.

The public is asked to inform a local trust if a water vole is spotted. Details should include the place where it was seen, the name of the nearest village, the date and contact details.

They can be recorded on a Know Your Vole postcard, available by sending an A5 sae to the Wildlife Trusts, Waterside, Mather Road, Newark, Notts, NG24 1WT, or on the trusts' web site, www.wildlifetrusts.org.

Yorkshire Wildlife Trust can be contacted on 01904 659570