ONCE championed by the loveable Ratty in the Wind in the Willows, water voles are now Britain’s fastest declining wild mammal.

Threatened by habitat loss and predation by the American Mink, this charming rodent has disappeared from many parts of the country where it was once common.

A report released last week by the national Wildlife Trusts group revealed the number of areas where water voles are found in the UK fell by 30 per cent between 2006 and 2015.

Oxfordshire, however, has revealed itself to be a surprise success story for Ratty.

The UK’s longest running water vole recovery project, led by the Berks, Bucks & Oxon Wildlife Trust, has reported a ‘significant and steady’ increase in water vole activity over the past 10 years.

Oxfordshire now boasts the two largest populations of the three counties.

The BBOWT team, working with the Environment Agency and the Canal and River Trust, have created a heaven on the Thames between Lechlade and Abingdon, including its own Chimney Meadows nature reserve.

The populations are continuing to expand and last year BBOWT recorded new populations on the River Leach close to the Gloucestershire border and the Frogmore Brook near Stanford in the Vale.

Project manager Julia Lofthouse explains: “Against the backdrop of a continued national decline in water vole populations, locally across our three counties our hard work has paid off and we have seen a steady increase in water vole activity through the years.

“In 2008 the total area of water vole activity in the three counties stood at 321km sq.

“This has increased by 78 per cent over the past 10 years to reach 603km sq in 2018.”

However Ms Lofthouse warned that some smaller populations are continuing to decline.

The national Wildlife Trusts network, BBOWT included, is now calling for local authorities to create a national Nature Recovery Network underpinned by a new Environment Act to protect, link and create areas of habitat which help wildlife move and spread out, benefitting a range of species.

It is also calling on landowners to manage riverbank habitat and on the public to find out more about volunteer opportunities.