What is a water vole?

Remember Ratty in Wind in the Willows? He wasn’t actually a rat as his name suggests, but was in fact a water vole! The name Ratty was probably derived from their other common name, the water rat, even though water voles only superficially resemble rats and are not that closely related to them. They are a semi-aquatic member of the Rodent family with the Latin name, Arvicola amphibius.

Water voles are much larger than most people realise, up to 9 inches long with a 3 inch tail on top of that. They are real ‘ecosystem engineers’, albeit on a small scale. This means that their burrows and feeding regimes mean that they can change how a habitat looks and functions over a period of time. This is all very positive as they create microhabitats which other wildlife can make use of.

They eat over 200 different kinds of plants, mainly in the sedge, rush and grass family. They will eat around 80% of their body weight each day, so it is crucial there is plenty of good vegetation present for them to munch on. Water voles do not hibernate, so during the winter they will dig up rhizomes and eat bark to survive as most of the green plants will be too tough for them to eat.

Water voles, not surprisingly, are only ever found close to water, and will rarely wander more than a few metres away from the waters edge. They form burrow systems in the bank edge, preferring to have an exit hole right next to the water, so they can escape from danger very quickly.

They will readily breed all year round, but conditions are usually only suitable for them from April to October, during which time they may have two or three litters. Since they rarely survive two winters it is imperative they breed as much as possible during their short lifetime. Not only do they have a naturally short life expectancy, they are also a prime prey species. Many of our native fauna feed on water voles, ranging from herons and owls, to pike and otters. It’s certainly a tough life for our friend Ratty! 

How do I know if I have seen a water vole (or found evidence of them)?

Water voles leave several tell tell signs behind when they have been living in an area. Or you might even be lucky enough to see one in the flesh!

Know your vole!

As previously mentioned, they are large, much larger than most people realise, up to 9 inches long (12 inches including the tail). They are usually a dark brown colour and have very small ears and a rounded face. The only other animal they might be confused with is the brown rat. Make a note of the following key differences between rats and water voles:

 

 

 

  1. Water voles have a rounded face. Rats have a pointy face
  2. Water voles have a shorter, furry tail. Rats have a long and scaly tail which is sometimes pink
  3. Water voles have small, inconspicuous ears. Rats ears are large and round
  4. Water voles will only be found near water. Rats can be found anywhere

 

 

Feeding remains

Cut shoots (R.Strachan)Water voles are strict vegetarians, with a diet consisting of over 200 different plant species, mostly sedges, rushes and grasses. They have extremely characteristic feeding habitats in that they will leave neat piles of vegetation with all of the ends cut at a 45 degree angle. You can also find stems with the angle on shoots growing out of the ground still – this is most common with thick stemmed plants such as hog weed. As well as leaving neat piles, they will also create feeding rafts. These are piles of cut vegetation that will be thick enough for a vole to sit on in the water. These are most typically found next to areas where suitable vegetation emerges directly from the water. Lastly, water voles will also create feeding lawns, particularly close to their burrows. These lawns are areas of extremely short cut vegetation, where the vole has grazed for a period of time.

Droppings and latrines

Latrine (R.Strachan)Another extremely characteristic feature of water voles is their droppings. Water vole droppings are lozenge shaped with rounded ends but vary in colour with freshness. They are similar sized to rat droppings, however rat droppings are extremely foul smelling. The unique thing about water voles is their tendency to create latrines. Water voles latrines are created as part of a territorial behaviour where a vole will revisit the same area over and over again to deposit its droppings. Because latrines are associated with territorial behaviour, they can be a really good indication to the number of voles using a stretch of bank. 

Burrows

Water voles create burrow systems along banks close to the water, however it can be extremely difficult to determine exactly whether they are water vole made or rat made. A fresh water vole burrow is unlikely to have any messy debris around it, whereas rat burrows will be muddy and often with feeding remains (such as snail shells, bones) scattered close by. Usually confirmation of a water vole burrow can only be found if other signs are found, such as latrines or piles of stems cut at an angle. 

Water voles and the law

Water voles have some legal status and protection in Wales. These are summarised below:

Wildlife & Countryside Act 1981 (and ammendments)

The water vole received limited legal protection in April 1998 through its inclusion in Schedule 5 of the Wildlife & Countryside Act 1981 (as amended) for some offences. This protection has since been extended (6th April 2008), so the water vole is now fully protected under Section 9.

Legal protection makes it an offence to:

  • Intentionally kill, injure or take (capture) a water vole; 
  • Possess or control a live or dead water vole, or any part of a water vole;
  • Intentionally or recklessly damage, destroy or obstruct access to any structure or place which water voles use for shelter or protection or disturb water voles while they are using such a place;
  • Sell, offer for sale or advertise for live or dead water voles.

Section 42 Species of principal importance in Wales (S.42)

The S42 list is used to guide public bodies when implementing their duty under section 40 of the Natural Environment and Rural Communities (NERC) Act 2006 “to have regard” to the conservation of biodiversity in all their activities, including during development planning.

UK Biodiversity Action Plan (BAP) priority species

UK BAP priority species were those that were identified as being the most threatened and requiring conservation action under the UK Biodiversity Action Plan (UK BAP).