Yorkshire Wildlife Trust is one of 47 local Wildlife Trusts across the country working together to create a better future for wildlife. YWT has worked for over 50 years to protect vulnerable wildlife of all types, and

the places where they live. We are the only conservation organisation working for all types of wildlife throughout Yorkshire. We care for 80 of the best nature reserves in Yorkshire – protecting the wildlife

where you live and making our county a better place for wildlife & people.

We always welcome new members to help us continue our important and valuable work throughout Yorkshire. To find out more

visit www.ywt.org.uk or email info@ywt.org.uk

Yorkshire Wildlife Trust, 1 St. Georges Place, York, Y024 1GN. Tel: 01904 659570 Fax: 01904 613467 Registered Charity No. 210807 Company Limited by Guarantee No. 409650

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What we are doing...

Water For Wildlife (WFW)

Yorkshire Wildlife Trust’s Water for Wildlife team work throughout Yorkshire to help safeguard water voles and to encourage the natural recovery of the species. The WFW projects are working to rebuild biodiversity along the Yorkshires rivers. They do this by:

Working with landowners, giving advice and practical help on managing and creating habitats for wetland species.

Surveying and monitoring for new and existing water vole populations.

Creating new habitat for water voles to protect existing colonies. Raise awareness about wetland wildlife,

their needs and the threats they face .

Increasing education about the importance of wetlands and wildlife through leaflets, talks and events.

Advising on mink control where necessary.

Yorkshire Wildlife Trust Protecting Wildlife for the Future

If you would like to know more or have information

about otter sightings, you can contact your local

Water for Wildlife Officer or visit our website for updates...

Website: www.ywt.org.uk

Email:

info@ywt.org.uk

Tel: 01904 659570

Postal Address: Yorkshire Wildlife Trust

1 St. Georges Place York

YO24 1GN

YORKSHIRE

Water Vole

Water Voles in Decline Once one of our most common mammals, water voles are now rarely seen along Britain’s rivers and streams. National surveys carried out in the 1990’s found that water voles had been lost from two thirds of their known sites. Yorkshire was one of the worst areas with 97% of popula-tions lost.

Water voles prefer slow flowing rivers, ponds, canals and reed beds with abundant bank side vegetation, for them to hide in and feed on. They suffer predation from a wide range of spe-cies including herons and weasels but are par-ticularly vulnerable to American mink. The mink breed very early in the season, can swim well and the females can fit inside the wa-ter vole burrows, rendering the water voles breeding and defence techniques ineffective.

Know Your Vole

Water vole Jon Traill

Water vole swimming Jon Traill

Water vole burrow and good habitat YWT

Fact Sheet Water Vole

Did You Know! Did You Know! The water vole is the largest member of the vole family in Brit-ain, with adults measuring up to 35cm and weighing between 150 and 300g. They are often confused with the brown rat which can be found in similar habitats, though rats grow up to 50cm in length and weigh up to 500g.

Water Vole and Brown Rat Ecology

Water Vole (Arvicola amphibius) Brown Rat (Rattus norvegicus)

Size and Shape

Rounded body. Adults grow to 30cm in length (including tail) and weigh up to 350g.

Adults grow to 40cm (including tail) larger than adult water voles and weigh up to 500g.

Colour Dark brown, reddish or black silky fur. Grey or grey brown fur, with a paler underside.

Snout, ears and tail

Short blunt snouts. Small ears almost hidden by fur. Furry tail two thirds of body length.

Pointed snouts and obvious large round ears. Scaly hairless tails same as body length.

Burrows 4 – 8cm in diameter. Close to water’s edge, but also with entrances on top of banks and under water. Grazed areas known as lawns often found surrounding entrance.

8 – 10cm in diameter occur further away from water, but also near waterline, so not always a reliable field sign. Sometimes have heap of soil in a fan shape at entrance.

Paths Usually one main track along waters edge, with some pushing up into bank side vegetation. Paths usually well concealed.

Network of well trampled paths connecting burrow, some leading well away from water.

Droppings In spring and summer droppings left in piles close to waters edge - latrines. They are 5 – 10mm long, rounded at both ends and have no strong odour. Can be confused with field vole

Scattered along rat runs, often away from water. They are 12 – 15cm long, flat at one end and pointed at the other. Sometimes strong, unpleasant odour.

Feeding Remains

Water voles have a mainly vegetarian diet. Small piles of half eaten vegetation such as grasses and rushes are left at feeding sites, often close to water’s edge. Pieces are around 10cm long and cut at a 45 degree angle with grooved teeth marks at one end.

Rats have a varied diet including insects and vegetation and are opportunist feeders. Feeding remains are not found very often. They sometimes predate on young water voles.

Activity Can be active during the day. More often seen at dawn or dusk.

Largely nocturnal.

Footprints Difficult to distinguish from a rat and are not a reliable field sign.

Difficult to distinguish from a water vole and are not a reliable field sign.

Destruction of suitable habitat causes isolation of colonies. Main causes are: canalisation, cul-verting, bank stabilisation and dredging of water courses. Overgrazing, excessive grass cutting and over-shading from scrub, trees and invasive plants also destroy water vole habitat.

Field Signs

Reasons for the Decline

Although water voles are fairly tolerant of people, they spend much time in their burrows and hidden in amongst vegetation, so we search for ‘field signs' or evidence to determine their presence and estimate numbers. Water voles deposit latrines of small, dark, sausage-shaped droppings along the range of their territories during the breeding season - from March to Novem-ber. Other field signs to look out for are ‘lawns' of closely cropped grass around tunnel entrances and neatly chewed piles of partially eaten vegetation. Water vole droppings YWT

In mild weather, breeding can take place from early spring, with an average of four to five young born below ground in grass-lined nest chambers. Young voles are weaned at the very early age of two weeks, and an adult female vole may have four litters of young in a breeding season.

Breeding

Current threats include:

PREDATION By the introduced North American Mink – released or escaped from fur farms throughout Britain. A single female mink can kill 50 – 100 water voles in one breed-ing season. Habitat fragmentation also increases the impact of other predators in-cluding domestic cats and dogs.

POISON Water voles are still mistaken for rats and vole colonies have been poisoned. In some areas the voles may be forced by flooding, into human areas where rat poison is used.

FLOODING Urbanisation and intensive agriculture can result in increased run-off of rain water, leading to flooding, which can destroy water vole burrows and wash rats into vole territories from storm sewers.

WATER ABSTRACTION This can lead to drying out of water courses, putting voles at risk from land predators such as stoats and weasels, because they can no longer dive under water as a de-fence.