Water Voles in Herts and Middlesex

Get to know Water Voles

Water Voles are one of our most well-loved wild mammals. They are sometimes confused withr Brown Rats, but you can tell them apart by their chubby round faces, plump bodies, and blunt noses.

They were once a common species in England, but are now classified as Britain's fastest declining mammal as over 90% of their populations have been lost since the 1960s. This is largely due to habitat loss and predation by invasive, non-native American mink. 

Water Voles need dense vegetation along waterways to survive as they eat about 80% of their body weight in food each day, which is mostly made up of wetland plants. They build their burrows along the water's edge and are very neat and tidy, some burrows even have trim lawns at the front!

Visit our Water Voles species page. 

Why They’re Important

Like beavers, Water Voles are fantastic eco-engineers as they munch away at vegetation and keep river banks in good condition.  By munching on vegetation, they prevent a few vigorous plants from taking over, allowing a wider variety of species to flourish. Their burrowing creates habitat for insects and helps shape healthy riverbanks. By eating and transporting seeds, they also encourage lush plant growth along waterways, benefiting countless other animals. 

Many of the places Water Voles once thrived in are no longer suitable for them. Intense grazing up to the water's edge, mowing and development has destroyed many habitats where water vole colonies once survived. 

But there is a more pressing problem facing Water Voles: predation by American Mink, a non-native mustelid that was bought to the UK and kept in captivity to supply the fur trade. The mink escaped, were released and began spreading throughout the country, rapidly consuming and reducing Water Vole populations.

Read more about American Mink here.

What We’re Doing

Here in Hertfordshire and Middlesex, we’ve set an ambitious goal: to have Water Voles thriving on every river by 2030. Achieving this means tackling threats like American Mink, restoring healthy wetland habitats, and carefully reintroducing Water Voles to rivers where they’ve been lost.

Reintroductions take careful planning. Before any release, sites are surveyed for habitat quality, mink control is carried out, and soft-release pens are used to give the animals the best possible chance to settle and survive.

Our Successes

In December 2024, a report from The Wildlife Trusts showed a national decline of 39% in occupied Water Vole areas since 2006. But here in Hertfordshire, there’s good news. Sustained conservation efforts mean that two river catchments in our counties have now reached “Regional Key Area” status, recognising their vital role in Water Vole recovery.

We have a proven track record in reintroducing Water Voles successfully to our counties’ rivers:

In 2015, the Trust reintroduced 188 to Thorley Wash Nature Reserve in the River Stort. This reintroduction relocated voles from further down the river near Clacton and released them up North to Thorley Wash. 

Read more about the Thorley Wash reintroduction here.

In August 2021, the Trust delivered another reintroduction of Water Voles in partnership with the Ver Valley Society into the River Ver. After a 34 year long absence of Water Voles, a stretch of the river now has a thriving population of voles after 150 were transported and released in soft release pens along the water's edge.

Read more about the River Ver reintroduction here.

River Beane (2022): Working with the Woodhall Estate and the River Beane Restoration Association, we reintroduced 138 Water Voles to a stretch near Watton-at-Stone. Bred in Devon by the Derek Gow Consultancy, these voles marked the species’ return to the Beane after more than 20 years.

Read more about the River Beane reintroduction here.

Reintroducing Water Voles is no mean feat. Considerable planning and preparation go into one reintroduction as steps to ensure the species will settle in the area and survive the harsh realities of a wild world for a Water Vole, must be followed meticulously. 

Read about how Water Vole reintroductions work here.