At River Thame Conservation Trust, we’re on a mission to bring back one of Britain’s most beloved and important riverbank residents: the water vole.

Once widespread across our countryside, the water vole (Arvicola amphibius) is now teetering on the edge of extinction in Britain. These charming creatures — made famous as “Ratty” in The Wind in the Willows — are more than just adorable. They are keystone species, shaping wetland ecosystems and supporting a wide variety of other wildlife. When water voles disappear, it sends ripples through the entire ecosystem.

The reality is sobering: water voles have vanished from 94% of their former sites. Between 2006 and 2022, their distribution declined by 39% across Great Britain. And the threats that drove them to this point — the spread of the invasive American mink, and the loss and fragmentation of wetland habitat — are still very much present.

Why Are Water Voles Disappearing?

The American mink — a non-native predator introduced to the UK through fur farming in the 20th century — has been a major factor in the decline of water voles. Mink are highly effective hunters and can quickly devastate local vole populations. Coupled with long-term habitat loss and degradation, it’s a combination that water voles have struggled to withstand without intervention.

Mink predation doubles the risk of local extinction for water vole populations. And because many of our rivers and streams are cut off from each other by intensive farming or built-up areas. These changes in land use have broken up the landscape, making it difficult for water voles to travel between habitats. As a result, once they disappear from a site, they’re unlikely to return without help.

Our Response: Coordinated Action for Water Vole Recovery

Since 2023, we’ve partnered with the Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust (BBOWT) to deliver a landscape-scale American mink control programme across the Thame catchment, as part of the wider “Joining the Dots” project.

Together, we’ve begun to tackle the mink problem at the scale needed to make a real difference — and the results are promising.

Since November 2023, we’ve:

- Deployed 65 mink monitoring rafts across 29 farms and 11 riverside landowners.

- Recruited and trained 61 dedicated volunteers, including landowners themselves.

- Successfully dispatched 45 mink since March 2024.

- Begun using cameras to track activity, with volunteers contributing vital data.

We’ve already seen signs that mink numbers in the Thame catchment are lower than last year, suggesting our efforts are working.

Even more excitingly, in 2024 we discovered what may be water vole footprints — the first encouraging sign of potential survival or recolonisation. While we haven’t yet found enough evidence to confirm their presence, we’re preparing to launch water vole surveys in 2025 to investigate further.

A Turning Point for the Thame Catchment

Unlike the Ock catchment, which has long been a focus for water vole conservation and still supports active populations, the River Thame has not seen confirmed, sustained water vole presence since the early 2000s. Past reintroductions — such as those at Cuddesdon and Chiselhampton in 2006 — were tragically lost to mink predation.

But with sustained effort and the support of local landowners, volunteers, and conservationists, we now have an opportunity to restore the River Thame as a thriving home for water voles once more.

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Our Next Steps for Water Vole Recovery:

We’ve developed a three-part strategy:

1. Habitat Enhancement - Restore degraded riverbanks and create mosaics of healthy wetland habitat to support future reintroductions.

2. Population Reinforcement - Buffer and connect areas of suitable habitat to create resilient metapopulations, and reintroduce water voles where appropriate.

3. Mink Control - Continue and expand our landscape-scale mink eradication programme to create a safer environment for water voles and other vulnerable species.

This approach has already worked across parts of England, and we know it can work here too — if we have the funding to continue.

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We Need Your Help to Keep This Work Going

Our water vole recovery work was kickstarted with funding from Natural England, but this has now come to an end. To continue this essential project, we’re turning to you — our community of supporters.

We’re thrilled to be taking part in the Big Give Green Match Fund, where every donation you make will be doubled at no extra cost to you. That means your impact goes twice as far in helping us protect the future of water voles and our river ecosystems.

One donation = twice the impact.

Donate through the Big Give Green Match Fund from 22nd to 29th April and help us bring back the water vole to the River Thame. Together, we can ensure that the story of water voles in our catchment doesn't end in extinction — but in recovery.

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