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Water vole

(Arvicola terrestris) Size: 167-209mm – 100-160mm tail Weight: 150-280g Lifespan: max. 3 years in the wild


Identification: Dark brown fur (occasionally black), rounded body, short chubby face with small protuberant eyes and small hairy ears, and a relatively short tail. General: Another elusive species, numbers have dropped dramatically (by 95% or so) over the last 30+ years following the widespread increase in the American mink population, following releases and escapes from mink farms. These very attractive mammals can be seen in the flesh, with patience, from the riverbank but their signs are easier to spot. Their droppings (c10mm long, c3.5mm in diameter, and often greenish in colour when fresh) are fairly distinctive, while feeding remains (stems of aquatic plants typically 10cm long and bitten off cleanly at an angle of 45 degrees) are more so. These are all best sought in early spring when river and stream-side vegetation is still quite short after the Latrine winter. Water voles live in burrow systems in river banks with holes along the waterline and some below. The systems open out on to the bank – these holes often have a ‘halo’ of nibbled grass round their edges. Distribution - UK: Widespread in the SE corner of the UK but with currently small isolated populations. Decreasing numbers towards the north and west of the UK, but present in Scotland and number of Scottish islands.



Cambridgeshire Mammal Atlas