Between 2008 and 2012 we carried out a water vole capture and release project in collaboration with Essex Wildlife Trust for the London Gateway development in Essex.
Darren Tansley at the Essex Wildlife Trust recently updated us on the progress of the water voles in their new location on the River Colne:
“We have been monitoring the voles since the final release in 2012 and despite some horrendous flooding they have done really well. They have now colonised most of the catchment and have been appearing along the small tributaries and in farm ditches along the valley.”
The water voles were captured in the autumn from areas designated for development on the site and kept over winter at a captive breeding facility at the Wildwood Trust in Kent. Water voles are short lived in the wild so captive breeding enabled us to increase the number of young animals available for the re-introduction.
The reintroduction site on the River Colne was identified two years before water vole release and surveys confirmed that water voles were absent. Historically they would have been present on the river; however, the presence of the introduced American mink has decimated water vole populations all over the UK.
We carried out a two-year programme of mink control, including monitoring and trapping, to make the river suitable before the water voles were released. Once the absence of mink was confirmed water voles were transferred from the breeding facility and were released on the river banks using specially designed release pens,. Some voles were radio-tracked for several weeks to monitor their progress and some of the release was filmed by BBC’s Countryfile programme.
In response to Darren’s feedback, David Prys-Jones, one of Thomson Ecology’s senior ecologists who worked on this project, said: “That’s great news. Of all the projects I’ve worked on, that’s the one I felt made the greatest difference.”
Thomson Ecology’s project manager for the London Gateway ecological mitigation works said: At the time this was by far the largest water vole mitigation project that Thomson Ecology had ever undertaken. It enabled us to develop an expertise in water vole mitigation techniques and establish a collaborative working relationship with Essex Wildlife Trust and Wildwood”.
Monitoring of the water vole population – and mink control when necessary – continue to be undertaken by local landowners and volunteers from the Essex Wildlife Trust.