What is a Water vole?

The water vole is the largest British vole species.  It is typically vole-like in its morphology  and a sighting of water vole is often confused with the bank vole Mypos glareous, field vole Microtus agrestis or the brown rat Rattus norvegicus although, the differences are easily identified with the brown rat being larger, with a non-furry tail, a more pointed nose and protruding ears. The field and bank vole being distinctly smaller in size.

In England and Wales their coat is generally chestnut in colour but be slightly darker or lighter and in Scotland their coat is variable tends to be darker and may be black. The water vole is an excellent swimmer although it does not have webbed feet. It uses the water to escape from predators by jumping in from the bank and whilst doing so, makes a loud plop indicating to other voles that danger is present. Once in the water they dive to the bottom and create a cloud from the sediment which temporally provides a decoy to escape into its burrows with some located underneath the waterline.

Diet

Water voles are herbivorous feeding on a host of different aquatic, wetland and marginal plants which may include reeds, grasses, rushes and sedges. During winter it has been known for other sources of vegetation to be eaten.

Preferred Habitat

Generally water voles prefer sites with wide swathes of riparian vegetation, both growing from the banks and from the water.

Water voles use a series of burrows which have many entrances, interconnecting tunnels, food storage and nest chambers. They live in colonies but spread themselves along a watercourse through a series of neighbouring territories.

Water voles prefer sites with a bank profile which is either of a steep incline (greater than 35°) or stepped levels with soil penetrable to allow excavation to aid the burrowing of nest chambers. The marginal and aquatic vegetation is also another important factor providing a food source and cover from predators.

How are Water voles protected?

The Water Vole is protected under schedule 5, section 9 of the Wildlife and Countryside Act 1981, under this act, it was illegal to damage, destroy or obstruct access to any structure or place which water voles use for shelter, protection and breeding and or to disturb a water vole whilst it is using such a place.

In April 2008 the water vole received full legislative protection and is now fully covered by the provisions of section 9 of the Wildlife and Countryside Act 1981 (as amended). Legal protection makes it an offence to: intentionally kill, injure or take water voles, possess or control live or dead water voles or derivatives, intentionally or recklessly damage, destroy or obstruct access to any structure or place used for shelter or protection, Intentionally or recklessly disturb water voles whilst occupying a structure or place used for that purpose, sell water voles or offer or expose for sale or transport for sale or publish or cause to be published any advertisement which conveys the buying or selling of water voles.  

As with all protected species law – there are exceptions and licences can be granted provided adequate justification is provided, in which case a suitably trained ecologist can translocate Water Voles to a safe place.

How to Survey for Water voles

A standard survey methodology for surveying water vole is recommended in the Water Vole Conservation Handbook (Strachan and Moorhouse 2006). This involves searching for field signs which are;

• Droppings and Latrine Sites

The presence of the water vole can be determined from its droppings, which provide the most distinctive field sign. They are roughly 8-12mm long and 4-5mm wide, cylindrical with blunt ends. Their colour ranges from black, brown and green, depending on age, diet and water content. Most droppings are deposited on latrine sites, which can be found at favoured areas where the voles leave and enter the water, at discrete sites near to their burrows and are used to mark territorial boundaries. Breeding voles use regular latrine sites along water margins, and often consist of a flattened mass of old droppings with fresh ones on top.

• Burrows

Water vole burrows have an approximate hole size of 4-8cm. The burrows can appear as a series of holes along the waters edge, some may open below the water line, whilst others can occur amongst the vegetation up to three metres from the water. Land holes may also show evidence of a closely cropped grazed lawn, where a female water vole has nibbled the vegetation short within easy reach of the burrow.

• Grazing Remains

Water voles often bring food items to favoured feeding stations along the waters edge and at burrow entrances. Feeding remains consist of neat piles of chewed off lengths of vegetation. These grazing remains typically measure 8-10cm, showing two large incisor marks. Grazing remains also double as food caches and are often accompanied by droppings.

• Footprints

Imprints from water voles show four digits from the fore foot and five digits in the hind foot. The imprinted digits form a star shape of splayed-out toes. Water vole tracks are very difficult to 5 distinguish between tracks made from the brown rat, particularly young animals. Generally, water vole prints tend to be much smaller than rat prints, but it is important to note that they cannot always be used as reliable indicators in the absence of other water vole field signs.