
Background
Throughout the 1900’s, water voles were a familiar sight on many water bodies across the UK. Immortalised as ‘Ratty’ in the classic childhood tale, The Wind in the Willows, water voles are also a key part of our ecosystem. Sometimes referred to as ‘mini beavers’, water voles constantly manage and micro-engineer waterways, with their foraging and burrowing increasing biodiversity to the benefit of many species, including other small mammals, bees, butterflies, insects, insect-eating birds, reptiles and amphibians and bats (https://watervole.org.uk/about/). In addition, they would ordinarily form a key component of the food chain, providing significant sustenance for terrestrial, aquatic and aerial predator species.
However, in recent years their numbers have fallen drastically, with reports identifying that they now occupy 97% less habitat throughout the UK compared to previous records. There are two primary drivers behind this decline; habitat loss and fragmentation, and the American mink – an introduced and invasive species.
American mink were originally brought to the UK for use in fur farms. However, during the 1950’s and 60’s many were either intentionally released by animal rights groups, or escaped themselves. The American mink is now widespread throughout Britain. As an active, generalist predator, mink have a very wide diet which includes water birds, amphibians, fish and our native water voles (American mink | The Wildlife Trusts).
Mink are semi-aquatic, with the smaller females being perfectly sized to access the burrows of water voles. Voles therefore have no safe refuge from mink. Without human intervention, it’s extremely likely that the precipitous decline in water vole numbers will lead to its extinction in the near future.

How can we prevent any further decline?
In a bid to halt this decline, several localised projects have been set up across the UK to control American mink. Floating rafts are placed at regular intervals along waterways which the naturally curious mink investigate, leaving identifiable footprints in clay plates. Once mink have been found to be present, a live-capture trap can be deployed. The trapped mink can then be humanely euthanised. As technology advances, it is now possible to attach a smart-device to a trap which sends a text message to alert you to a capture, meaning that rafts can be deployed in permanent ‘trap’ mode, thereby reducing effort and increasing capture rates.

One of the leading mink control projects is the Waterlife Recovery East (WRE) project in East Anglia. Spanning across the counties of Norfolk, Suffolk and Essex, the WRE has over 700 ‘smart rafts’ and countless volunteers to monitor and dispatch mink. The results are impressive, with early indications suggesting that in their core area mink numbers have been reduced significantly, bolstering the idea that it is possible to eradicate, rather than just control mink across the UK.
However, despite many groups and organisations undertaking mink control in the UK, there is no coordinated effort or understanding of the geographic extent of control. This results in all projects needing to be constantly vigilant to mink migrating in from outside of ‘their’ control area. And given that migrating mink travel large distances, this is a constant concern. Until there is a cohesive approach to mink control, mink eradication is impossible; mink will continue to traverse our waterways, moving into control areas and predating water voles and other aquatic fauna. Thus we will have a never ending cycle of ongoing mink control.
The only way to change this is to create one single point of recording and monitoring mink numbers, bringing groups and individuals together across the country. This is where the Mink MApp project comes in.
What is Mink MApp?
Built using Coreo, the Mink MApp app was designed by Dr Merryl Gelling, Director at Spires Ecology and an expert in water voles. The aims are to unify current mink control initiatives; encourage the initiation of new projects; and to provide a robust basis from which a nationwide strategy may be developed.
The app enables users to securely record a raft location and type and update the details of this record everytime a raft is checked, so they can log what they’ve found. No data will be publicly available, but the data will be used centrally to identify where mink control is ongoing, and, importantly, where there are geographical gaps in mink control.



By understanding current mink control across the UK, we can ultimately develop a nationwide strategy for mink eradication.
“I’ve been working with water voles for over 20 years, undertaking research into causes of decline and ways in which we can reverse this trend. In that time, despite understanding the primary issues and what we need to do, water voles have continued to decline in both numbers, and areas of the UK in which they are found. Working with Coreo to develop the Mink MApp has given me the first glimmer of hope in a long time that we can come together to resolve this issue. It’s free, secure and easy to use and provides a really powerful tool for us to understand where mink control is currently ongoing, and how we can work together to extend it.
“We are running out of time to save the water vole in the UK for future generations, and I don’t want to have to look my children in the face and explain that, despite knowing what we had to do, we let ‘Ratty’ go extinct in our lifetime.” – Merryl Gelling
Keep an eye out over the coming months where we will be catching up with Merryl to find out how the project is progressing.
To learn more about the Mink MApp project and find out how to sign up, head over to their website.
Or, if you’d like to find out more about Coreo and how it could help your project, then please get in touch.