Water voles in Herts and Middlesex

In the 1970s, water voles were a common sight for passers-by around waterways across the country. Now, only 10% of the former population survives in waterways in the UK. Such drastic declines have come about through habitat loss, water pollution and predation by invasive non-native American mink.

All about water voles

Water voles are chestnut-brown furry mammals that live in waterways such as rivers, streams, ponds, lakes and marshes. They are about the same size as brown rats, although they are distinguishable different from rats by their round chubby faces and bodies and blunted 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 1970s. 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. 

Like beavers, water voles are fantastic eco-engineers as they munch away at vegetation and keep river banks in good condition. 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.

Reintroducing water voles in Herts and Middlesex

The Trust want to see water voles in every river in Hertfordshire, and so have been delivering reintroductions of the species over the past decade. 

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.

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.