Threatened by habitat loss and mink, water voles have been popularised by 'Ratty' from The Wind in the Willows. This much-loved character found along our network is one of our most endangered species.
The vole's burrowing and digging helps maintain ecosystems for other animals and plants to thrive.
Scientific name: Arvicola amphibius
Family: Cricetidae
Diet: Grasses and waterside vegetation
Predators: Mainly American mink. Also, foxes, otters, stoats, weasels, brown rats, owls, herons, and pike might prey on water voles
Size: 14-22cm long with a 9.5-14cm tail
Weight: 150-300g
Lifespan: Six months to around two years
Ecosystem engineers
Not to be confused with its widespread cousin, the rat, the water vole is the largest British vole. They're water-loving creatures, similar looking to brown rats, but with a blunter nose, smaller ears, and fur on their tails.
Kenneth Grahame's classic The Wind in the Willows popularised the animal. Although sometimes referred to as a 'water rat', Ratty is a vole – there is no such thing as a water rat.
Water voles are ecosystem engineers. Like mini beavers, voles manage the waterways by foraging and burrowing to increase biodiversity. Their work benefits many species, including bees, butterflies, insects, birds of prey, and bats. Waterways with higher numbers of water voles have richer vegetation and plant life.
Threatened by American mink and habitat loss, water vole populations are under serious threat. We've been working to highlight the vole's decline and boost numbers.
Water voles and our canals
We are always mindful of potential water vole habitat when carrying out works along our canals and rivers. Wherever possible, we incorporate vole-friendly banks into our routine works to extend habitats for this well-loved waterway creature.
Water voles have dark chestnut-brown fur with a blunt, round nose, short ears, and a furry tail. They're similar in size to rats and much bigger than other voles. In Scotland, water voles are typically darker with black fur. Although it looks similar, the brown rat tends to have grey-brown fur, a pointed nose, larger ears, and no fur on its tail.
A small, furry brown water vole with short ears, small hands, and a hairless tail crawls through grass and leaves.
What do water voles eat?
As herbivores, water voles eat a variety of plant life. In the summer, they eat over 200 different grasses and waterside vegetation. In the winter, they eat roots, bark, berries, and other foods stored in underground caches.
Water voles will eat about 80% of their body weight each day.
How do water voles breed?
Water voles can have three to six litters a year. In mild weather, the first litter can be born as early as March or April. In colder years, breeding might be delayed until May or June. Each litter has about five young, born in underground nests made from grass and rushes.
Young water voles are blind and hairless. They grow very quickly, leaving the nest after three weeks. Pups can breed themselves after 15 weeks.
Voles have short life cycles, with most not surviving more than one winter.
Water voles live in much of Europe and parts of northern Asia. They tend to make their homes within 10-15 metres of water and never stray far from their burrows.
Voles like rural areas with dense vegetation. This affords them some protection from the searching eyes of predators, mainly mink, which have contributed to the water vole's decline. Slow-flowing, deep water, like canals, lakes and streams, suit voles, who do not have the webbed feet of most water-dwelling animals.
They burrow into steep canals or riverside banks to form a complicated system of underground tunnels and nesting chambers. Voles build their burrows by biting into the earth with their strong enamel-coated teeth. Intelligent voles construct burrows on several levels to minimise the risk of flooding. At least one entrance will be below the water level for a fast escape if necessary.
Voles have slow, doggy-paddle-style swimming strokes – are a treasured sight on our canals and rivers. They make a characteristic and distinctive 'plop' noise when jumping into the water. You can often see them swimming with most of their body above the water. They also sometimes swim completely underwater.
That said, they're clumsy swimmers with bodies not well adapted to water. As such, water voles can sometimes lead terrestrial (on-land) lives.
If you're keen to spot a water vole, look out for grazed 'lawn' areas. They're often covered with neat piles of chopped grass, seen around burrow entrances.
Voles tend to sit and eat in the same places, and you might find evidence of their meals along our water's edge. Look out for grass and stems nibbled with a distinctive 45-degree angle.
What's the best time of day to spot water voles?
Water voles are most active during the day, and they spend their time eating in the open. You might also see them collecting grass, reeds, and other waterside vegetation to store in their burrow for the cold winter months.
What's the best time of year to spot water voles?
You're most likely to see voles on our canals between April and September because the vegetation along the banks is shorter.
Once a familiar sight, water voles are now a rarity in Britain. Habitat loss and the invasive American mink have resulted in a 97% decline in the last 50+ years. Water voles are legally protected in Britain, and we're making efforts to restore populations.
