Formerly common throughout mainland Britain, the water vole has suffered the most dramatic decline of any mammal in the UK over the last century.
The water vole is immortalised in Kenneth Grahame's Wind in the Willows as the character Ratty. And at the time the book was written, water voles were a common fixture of British rivers, ditches, lakes and ponds.
In the 100 years since the book was written, water vole numbers have dropped to a tiny proportion and they are now unknown in some areas of the country.
Water voles make their burrows in grassy banks. Loss of this habitat to development, and due to concreting waterways and more intensive farming methods, has played a major part in their long-term decline.
In the 1950s American mink escaped from fur farms, colonising the countryside. Their voracious predation on water vole has compounded their decline. Mink are now the water voles main predator.
Unfortunately, many people wouldn't know a water vole from a rat and so many more have been killed where rodenticide has been spread indiscriminately.
The water vole population is now so small and fragmented that water voles can be wiped out forever in an area by a single incident. They are now fully protected under the Wildlife and Countryside Act 1981.
WWT Conservation Action
WWT is proud to be home to water vole populations at six of its Wetland Centres. Water voles are present at Llanelli, Martin Mere, Slimbridge and Welney Wetland Centres. WWT has also reintroduced them to Arundel Wetland Centre and, most notably, successfully introduced them to the London Wetland Centre in 2001 with the Environment Agency.
The Wildfowl & Wetlands Trust (WWT) actively works to maintain and then expand water vole numbers where suitable on all the land it manages.
Where water voles are present they are a primary consideration in managing the sites, not least because they are an indicator of the general health of the wetlands.
London
With the Environment Agency, WWT introduced a population of 250 water voles to London Wetland Centre, beginning in May 2001. This population has now established and flourished to between 3-400 individuals.
WWT actively manages the habitat and controls pests to maintain water vole numbers and give them the opportunity to increase their numbers and expand their range.
Work is led by the reserve wardens working with volunteers. It includes keeping the vegetation low in particular areas to create dense corridors - water voles use these to travel between sites in safety - and protecting the area from American mink and foxes.
The other side to the work is monitoring water vole numbers to measure the success of the project. Data is built up in part from professional surveys but sightings reported by the public play a large role as well.
Water vole platforms have been put in ten places around the London Wetland Centre where water voles are known to be active. Three of these are used as feeding platforms and are ideal for the public to spot water voles.
Sightings have increased steadily and on one feeding platform in particular sightings are sometimes almost daily.
Arundel
Water voles were reintroduced to WWT Arundel Wetland Centre in 2005. The voles have started breeding and dispersed around the site. The boat safari at Arundel is the ideal place to see water voles and sightings are regularly reported.
Slimbridge
Water voles are doing well in the reserve. Visitors also regularly see water voles in the pool by the ramp at the front of the centre. WWT is working with Gloucestershire Wildlife Trust and EA on a plan to expand the population into the wider Berkeley Vale area.
Llanelli, Welney and Martin Mere
All these sites support healthy populations of water voles in the wider reserve. WWT staff are working hard on site to create the best habitat possible for water voles.