Land Management for Water Voles Arvicola amphibious: A Practical Guide
17 October 2024The water vole has chestnut-brown fur, a blunt, rounded nose, small ears, and a furry tail. It is much bigger than other vole species, almost the size of a guinea pig. Scotland’s water voles often appear darker, with many having a black coat because their genetics is thought to originate from a different place than English Water voles. They are smaller and rounder than rats which have pointed ears and sharp noses. This cute looking animal is affectionately know as “Ratty” in Kenneth Grahame’s book “Wind in the Willows”
Key messages for managing water voles:
- Don’t cut or heavily graze bankside vegetation between March and September.
- Cut banks alternatively each year or only one side of the bank but don’t cut it short.
- Leave a 2m to 5m strip along the banks to support vegetation but not trees and scrub.
- Protect bankings from poaching by livestock.
- Prevent mink using the area by trapping them.
Water vole © image Dave Russell Pixabay
Status of Water Voles in the UK
Water voles receive protection under the Wildlife and Countryside act 1981 (as amended). It’s an offence to intentionally or recklessly damage, destroy or obstruct access to any structure or place used by water voles for shelter or protection.
Water voles are also protected against disturbance while within such structures.
They are a Priority Species under the UK Post-2010 Biodiversity Framework and are listed as endangered on both the Great Britain and the England Red List for Mammals.
Why are they special
Water voles are a vital part of river ecosystems. Their burrowing, feeding and movements help to create conditions for other animals and plants to thrive. We can think of water voles as ecosystem engineers. These ‘mini beavers’ constantly manage and micro engineer waterways for the benefit of wildlife and us. Their foraging and burrowing increases biodiversity for the benefit of many species, including small mammals, many species of bees, butterflies, insects, insect-eating birds, birds of prey and bats
In the 1900’s there were around 8 million water voles in the UK. They were widespread and commonly heard or seen in almost every slow flowing waterway in the British Isles, from northern Scotland to the tip of Cornwall. Today it is completely different, the chance of an encounter is rare, because they are nationally scarce, and their numbers are estimated at only 100,000 across the UK.
Threats to Water Voles
The declines of Water voles have been documented for the following reasons;
- intensification of agriculture following the first world war, when bank side vegetation was removed and areas heavily grazed
- Fragmentation of habitats as bankside vegetation was lost leading to populations that can no longer interact and spread.
Mink which escaped or were released from fur farms caused further dramatic water vole declines. A breeding female mink is small enough to enter water vole burrows and can cause the extinction of a water vole colony in one breeding season.
Damaged water margin©H Bibby
Habitat requirements
Water voles usually live beside slow moving water courses, where they feed on grasses and herbs growing on the banks. They dig their burrows here too. Water voles prefer sites with steep or stepped bank profiles into which they can burrow to create nest chambers above the water table. Soft soils are preferred. They prefer water bodies with tall waterside vegetation such as long grass and herbs for cover and food.
A water vole will even inhabit a ditch with slow flowing water. They require plenty of vegetation growing from the banks and emerging from the water to provide food and cover from their predators and clean water. They need wide vegetated margins, at least two metres (ideally five metres) of uncut bank-side vegetation until the end of the breeding season.
This is vital, as a water vole needs to consume the equivalent of 80% of its body weight in food each day and a breeding female double that amount. If a water vole has a plentiful supply of food, its population can increase rapidly.
Banks and emergent vegetation need minimal management. They depend on water margins not being cut or heavily grazed between March and the end of September.
Well managed water margin ©H Bibby
They prefer soft, undisturbed earth banks which they can burrow into with wide margins which have tall grasses, stands of rosebay willowherb, purple loosestrife, meadowsweet, or nettles, often fringed with emergent rushes, sedges or reeds, to give them food and cover. They will gnaw on the roots and bark of sallow and willow, as well as the rhizomes, bulbs and roots of herbaceous plants during winter. Water voles can also inhabit extensive reed-beds where they weave rugby ball-sized nests made of reeds. They do not like woodland or scrub as the shading causes loss of grasses and herbs.
How to help water voles thrive
It is easy to provide a home for water voles, so that populations can thrive or expand.
Create grassy buffer strips along watercourses, ditches and in-field ponds. Ensure that there is plenty of vegetation growing from the banks and emerging from the water to provide food and cover from predators and ensure the water is not polluted. Water vole conservation relies on maintaining tall grasses and herbs alongside the water body therefore don’t graze or cultivate within 2m – 6m of the edge of the watercourse. An off-stream pasture pump enables livestock to access water from the water course without needing to access the waterway directly.
Water vole sensitive management©H Bibby
It is best to manage habitat by cutting alternate sides of the bank, or only one side of the bank every 3 to 5 years to maintain cover and control scrub. Don’t cut it too short, maintain 15cm, so that some cover is maintained and only cut between October to February. Don’t spray with chemicals.
The growth of dense scrub or trees is damaging as it leads to a decline in the grasses, reeds, sedges and rushes that the voles eat. They can live happily under light brambles often feeding on the leaves and berries.
Prevent the colonisation by mink. Targeted mink control will really help. If you already have water voles this may be the most important management to carry out.
De-silt ditches on a five-year rotation carrying out work during the winter months. Deposit the silt away from the banking. Keep machinery to one side of the waterway and away from the edge of the bank. Avoid de-silting more than half a ditch in any winter.
Further sources of information can be found at Watervole.org.uk
Water vole habitat in winter©H Bibby
Thanks for subscribing! Please check your email for further instructions.
Related articles
Habitat and Landscape Management
Sign up to the FAS newsletter
Receive updates on news, events and publications from Scotland’s Farm Advisory Service