The Water Vole is the largest of the British voles (others are Bank, Field and Orkney voles) and is about the size of a Brown Rat. Its fur traps air, providing thermal insulation when swimming, and it has flaps of skin in the ears which prevent water from entering. However it has no webbed feet and its fur becomes waterlogged after long periods in the water. Water Voles are sometimes mistaken for Brown Rats which also often live near water courses; however, Water Voles have a more rounded body, blunter nose, larger eyes and less obvious ears than rats.

The Water Vole is widespread throughout Britain but is generally restricted to lowland areas beside water and is less common on higher ground. It is rarely recorded from parts of northern Scotland and is absent in Ireland. Water Voles’ preferred habitat consists of densely vegetated banks of slow flowing rivers, ditches, lakes and marshes where water is present throughout the year.

Water Voles live in colonies, divided into individual and contiguous territories. These territories are established by breeding females and are marked by latrines (piles of flattened droppings) and scent markings. The burrows have many entrances, tunnels and chambers (used for food storage and nesting). Several horizontal layers of burrow act as insurance against flooding and there is usually an underwater entrance to provide the voles with a safe route in and out. The Water Vole is herbivorous, feeding on a wide variety of waterside vegetation including sedges, rushes and reeds. They can give birth to 3-7 pups in a litter and usually produce two or three litters a year. In winter, they do not hibernate but become less active above ground.

Water Voles have suffered a dramatic decline this century and their widespread distribution is increasingly threatened. Factors affecting Water Vole populations include habitat loss and fragmentation from agricultural drainage and intensification, riverbank modification, pollution, canalisation of rivers and poisoning by rodenticides. Predation by American Mink (Mustela vision) is now also seriously affecting Water Vole numbers as the Mink swims expertly and can reach into Water Vole burrows. Mink may even cause local Water Vole extinctions. Large and robust vole populations supported by good quality habitat can better resist Mink predation by improved predator avoidance in dense vegetation and by providing more alternative prey items to the Mink.


The Water Vole is a UK Biodiversity Action Plan (BAP) species and is included on Schedule 5 of the Wildlife and Countryside Act 1981 (as amended), section 9(4). This protects places of shelter and protection, but does not protect the Water Voles themselves. In practice this makes it illegal to:

damage, destroy or obstruct access to any structure or place which Water Voles use for shelter or protection;

disturb the voles while they are using these places.

When considering planning applications, the authorities are required by law to take account of protected species and the conservation of habitats. A detailed ecological survey is usually required before planning permission can be granted.




Water Vole presence can be determined by field signs during the breeding season, when it is most active above ground. The survey period is weather dependent but runs approximately from April to September. Field signs include droppings and latrines, burrows, grazed lawns around burrow entrances, and feeding remains. Survey at other times of year is unreliable, as burrows may be created by Brown Rat and other signs are less evident during the winter and are easily washed away by heavy rain or high water levels. For this reason, an absence of signs at any time of year needs to be treated with caution.


Intentional damage to burrows cannot be licensed for development or maintenance operations. To avoid committing an offence, all reasonable steps must therefore be taken to minimise damaging actions to burrows and mitigation is needed when development cannot be altered and will potentially affect Water Vole habitat. This may include excluding Water Voles from the area of works, the provision of alternative habitat, or as a last resort translocation of the colony.