Water vole  (Arvicola terrestris)

The water vole is widely distributed throughout Europe from the UK to eastern Siberia (5). It is widespread throughout Britain but is generally restricted to lowland areas beside water (2). Once a very familiar mammal of the British countryside, the population has undergone one of the fastest and most serious recent declines of any British mammal (5). The species has been in decline for many decades (6), and a national survey in 1996 to 1998 showed that the water vole had been lost from a massive 94 percent of sites (5) and had vanished from entire catchments in northeast Scotland, North Yorkshire and Oxfordshire (5).

Prime water voles sites are found along densely vegetated banks (2) of slow flowing rivers, ditches, lakes and marshes where water is present throughout the year (5).