Water voles thriving on Exmoor just four years after being released

  • Watch footage of one of the voles at Holnicote.

Water voles are thriving on Exmoor, just a few years after they were reintroduced.

The little mammals, who inspired 'Ratty' in Kenneth Grahame's Wind in the Willows, are under threat from habitat loss and predation by the American mink.

But they've found a safe haven on the Holnicote Estate in West Somerset, where 300 water voles were released in 2018.

Jack Siviter, area ranger on Exmoor, said the creatures have now spread to every part of the river catchment.

Water voles are one of the species under threat from habitat loss and predation by the American mink Credit: National Trust images, Richard Bradshaw

"We've found them pretty much everywhere we've looked," he said.

"Any voles that were in the original release will have perished by now, so the ones we’re seeing are definitely their descendants."

Water voles look similar to the brown rats, but with a blunt nose, small ears and furry tails.

They only live for around 18 months and can breed up to four times a year, with four or five kits per litter.

Although they are widespread throughout the mainland UK, their range and numbers have significantly declined.

This is largely due to American mink escaping or being released from fur farms in the 1960s.

The American mink is thought to have been introduced by fur farmers in the 1950s Credit: SNH/PA

Mr Siviter said: "Mink are small enough to get inside the voles’ burrow network, so the voles don't stand a chance really.

"I have only seen one mink on our trail cams so we’re pretty sure we’re mink-free on Exmoor, due to hunting historically, which is part of the reason we reintroduced the voles.

"We also now have otters on all our rivers and they suppress the mink.

"They'll eat vole too if they can, but they can't get into their burrows the same."

Water voles can breed up to four times a year, with four or five kits per litter Credit: National Trust images, Richard Bradshaw

Water voles live in burrow networks with entrances around the size of a ping-pong ball.

They mow little 'lawns' outside their burrows and use piles of poo to mark their territory.

'Latrines' of rounded, cigar-shaped droppings may also be spotted. 

They like to sit and eat in the same place, so piles of nibbled grass and stems may be found by the water's edge, showing a distinctive 45-degree angled cut at the ends.

Jack added: "We’re still monitoring water voles all over the estate. If they are still here in 20 years we’ll know we’ve succeeded."

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