Water voles in the Brecon Beacons National Park

The water vole is one of our most endangered species. Previously widespread, it can now be found in just a few scattered places in the UK.

It’s possble that it’s extinct within the Brecon Beacons National Park, but it’s hoped that it survives in isolated populations in the uplands, where it is left undisturbed by either man or mink.

In Kenneth Grahame’s The Wind in the Willows, Ratty the "water rat" was actually a water vole. Even now, water voles are often confused with rats are they’re vaguely similar in size and appearance. Water voles however have a blunt nose, chestnut-brown fur, short rounded ears and short hair-covered tail. Rats have larger ears and hairless tails.

Able to swim and dive with ease, a tactic that helps them avoid predators, water voles are usually found near open water. They dig their burrows on well vegetated banks of slow flowing rivers, ditches, dykes and lakes, feeding on grasses and waterside vegetation. They tend to be active more during the day than at night.

Water voles usually have three or four litters a year, depending on the weather. In mild springs the first of these can be born in March or April, though cold conditions can delay breeding until May or even June. There are about five young in a litter, which are born below ground in a nest made from suitable vegetation, notably grasses and rushes. Although blind and hairless at birth, young water voles grow quickly, and are weaned at 14 days.

On average, water voles only live for about about five months in the wild. Their most significant predators are mink and stoats. Herons, barn owls, brown rats and pike are also known to hunt them.