Water vole

When: All year

Scientific name: Arvicola amphibius

Gaelic name: radan uisge or lamhallan

Size: Adults grow up to 20cm, plus a tail of around 10cm

Where: Along riverbanks or in marshy ground

Commonly mistaken for a small rat, water voles are the largest species of vole in the UK, and can be seen foraging along waterways throughout the year. Unfortunately, water voles have suffered a distinct decrease in population due to loss of habitat and predation from other species.

Most famously depicted as Ratty in the Kenneth Grahame's children's classic 'The Wind in the Willows', water voles can be mistaken for their rodent cousins thanks to their chestnut brown fur and long, worm-like tail. However, there are some subtle differences that can help you to tell these two similar species apart; water voles eyes and ears are very small, almost hidden in their fur. Their faces are much blunter than a rat's, which are often characterised by their pointy snouts. Rats are not the only animals that water voles have been likened to - if you hear someone speak of a 'water dog', 'water mouse' or 'earth hound', they may also be referring to this little freshwater mammal.

Water voles are herbivores, however they are not fussy when it comes to what plants they will eat. The entrance to one burrow was found to be littered with the remnants of 227 different species of vegetation! Most commonly, they will eat grasses and sedges in the summer and tree bark and berries in the autumn and winter. Some individuals may eat small invertebrates to sustain them when other food is scarce. They are also prolific breeders - a mating pair can rear up to three litters in one season, each baring two to five pups! Not all the young will survive however, due to predation from larger mammals such as American mink and foxes, and birds of prey such as owls and marsh harriers. 

Scottish water voles are actually set apart from their counterparts south of the border. Water voles in England and Wales are said to have originated in south-east Europe, recolonising mainland Britain after the last Ice Age. In Scotland, it is supposed that water voles are actually descendants of migrants from the Iberian Peninsula, in northern Spain. This is reflected in their slightly darker coloured fur, compared to their southern relatives.

If you want to learn more about water voles, you can find more information at https://ptes.org/get-informed/facts-figures/water-vole/ - You can even help to monitor their population be recording a sighting - https://ptes.org/get-involved/surveys/countryside-2/national-water-vole-monitoring-programme/

Image: Ben Andrew, RSPB Images