Bank vole

The bank vole is a small rodent resembling a mouse when young but developing a stouter body, a slightly rounder head with smaller ears and eyes and a shorter, hairy tail. The dorsal surface is reddish-brown, with a greyish undercoat and the flanks are grey with a reddish-brown sheen. The underparts are whitish-grey sometimes tinged with dull yellow. The ears are larger than those of most voles. The adult head and body length varies between 3.25 and 4.75 inches (83 and 121 mm) and the tail ranges from 1.5 to 3 inches (38 to 76 mm). The weight is between 15.4 and 36 grams (0.54 and 1.27 oz). Young animals are darker in colour with greyer underparts. The bank vole is capable of making growling sounds and can utter low-pitched squeaks. In a case of distress and isolation it has been witnessed to emit a sound resembling that of a human sob. In areas such as Great Britain, where the only other small vole is the short-tailed vole (Microtus agrestis), the bank vole is distinguished by its more prominent ears, chestnut-brown fur and longer tail which is usually 50% body length. The northern red-backed vole (Myodes rutilus) from northern Scandinavia and Russia, has a shorter tail and is paler with less grey in its pelage. The grey red-backed vole (Myodes rufocanus) from northern Eurasia, is larger with a distinctive reddish back.