No.047 · Mammals · Rare
Water vole
Arvicola amphibius
Ratty of Wind in the Willows: a chestnut vole with a blunt nose that plops into the water. One of Britain's fastest-declining mammals, now slowly recovering in the Broads.
When to look
April to September, mostly at dawn, day and dusk.
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Time of day
- Dawn
- Day
- Dusk
- Night
- Best time
- Day, April–October; peaks in warm mornings.
- Where in the game
- the Norfolk Broads (fen and grazing marsh) and Millbrook (canal)
- Size
- Body 14–22 cm, tail 9.5–14 cm
- Weight
- 150–300 g
- Lifespan
- Average 6 months–1.5 years in the wild
- Population
- About 132,000 in Britain (Mammal Society, 2018; 95% CI 99,000–329,000)
- Status
- Endangered in Great Britain (Mammal Society Red List for Britain)
Diet
Grasses and waterside plants, plus roots, bulbs and fallen fruit; needs to eat about 80% of its body weight each day (PTES)
Habitat
Slow-moving dykes, ditches, canals and streams with bankside vegetation
Breeding
Breeds roughly March–October; gestation 23 days; 3–5 pups per litter; 5–6 litters a year (Mammal Society).
Field signs
- Loud 'plop' when entering water
- Latrines of tic-tac-sized droppings
- Grass stems nibbled at a 45-degree angle, in small piles
- Star-shaped front footprints in mud
Did you know?
- Water vole numbers have fallen by about 90% since the 1970s (Mammal Society).
- In the Broads, numbers have begun to recover since American mink trapping began in 2003 (Broads Society).
- A water vole needs to eat about 80% of its body weight every day (PTES).
Moments worth waiting for
- Feeding on a grass stem
A water vole holds a stem in its paws, nibbling like corn on the cob. - Swimming across
A vole paddles across the dyke, head just above the surface.
Photo tip
Sit quietly near a dyke or canal in the morning with a long lens; look for grass moving.
Be a good naturalist
Protected: never disturb burrows; keep dogs away.
The law
Protected under Schedule 5 of the Wildlife and Countryside Act 1981, including its burrows and nests: it is illegal to kill, injure or disturb it or damage its shelter.