“Believe me, my young friend, there is nothing - absolutely nothing - half so much worth doing as simply messing about….” – with mink rafts. (With apologies to Kenneth Grahame)

29th January 2025

On a blustery and rainy Wednesday morning, six ‘active participants’ from Wildlife Groundswell, together with two representatives from Natural England, met with David Carrier of Kernow Conservation CIC at Rosuick Farm to learn about mink rafts.

David, who is based alongside the Trelusback Foundation for Wildlife Conservation near Redruth, is working with the Waterlife Recovery Trust with the aim of reintroducing water voles to Cornwall.

Ratty, famously in The Wind in the Willows, was just such a creature. Once a familiar sight along our riverbanks, the water vole (Arvicola amphibius) – with its blunt nose, small ears and furry tail – is the UK’s fastest disappearing mammal, facing extinction from habitat loss and predation by the American mink.

A recent wildlife survey showed a 94% drop in water vole numbers from their healthy population of about 8 million of a century ago – when Kenneth Grahame wrote his evocative tale. Enlisted as an endangered species in England and Wales, and threatened in Scotland, water voles have vanished entirely from many parts of Britain and absent on islands such as Scilly.

As a keystone species, water voles play a role similar to that of beavers in helping to maintain a healthy wetland ecosystem.

As a generalist predator, the American mink (Neovison vison) is classified as a damaging non-native species in the UK under the Wildlife and Countryside Act (1981). Members of the mustelid family, they are related to species such as badgers, otters, polecats and stoats. In size, they are much smaller than an otter but larger than a stoat and similar in size to a polecat or domestic ferret.

Escaped or intentionally freed from fur farms in the 1960s – when the farming of mink was made illegal – the American mink became well established across the UK. Carnivorous in nature and able to enter burrows, mink pose a major threat to our native water vole, as well as to ground-nesting seabirds.

In Cornwall, the water vole became extinct, with its last reported sightings in the 1990s, and did not return until the first reintroductions were made in Bude in 2014. Further successful reintroductions, including along the River Kennall in 2022, have established some remarkable stretches of habitat. But in all of Cornwall’s 130+ waterways, water voles are still only found in five of them.

David has several more sites under consideration for water vole reintroductions. Careful monitoring of potential sites, requiring help from volunteers, is first undertaken to ensure the absence of mink. This currently involves using paired traps – one on land and another on an adjacent raft. Here, on The Lizard, there are five sites where paired traps have already been deployed.

All traps are fitted with an electronic device which, when triggered, sends a mobile signal to David. He then contacts a locally-based volunteer who will check the trap and report back.

All the traps are baited with a strong mink lure that needs replacing every six months - which David will do. The lure and design of the trap ensures that other animals – such as grey squirrel or brown rats – are very unlikely enter the trap. If a mink or grey squirrel is trapped it is destroyed (by David). (Under the Wildlife and Countryside Act 1981 it is currently an offence to release grey squirrels without a licence). Other trapped species need to be reported and released by the monitor.

All trap locations are reported using the MinkMapp app.

Wildlife Groundswell’s Action Plan:

· our active participants will liaise with David as to whether they would like to monitor a current site and/or suggest alternative site(s)

· David will decide whether to retain the current trap positions or to consider alternative sites suggested by Wildlife Groundswell

· everyone to remain alert to any reports of mink sightings on the Lizard and inform David accordingly

If you are interested in becoming involved please contact wildlifegroundswell@gmail.com

Water voles versus mink

STREAM TESTING