Water voles are an endangered species in the United Kingdom and have suffered the greatest decline of any British mammal since the latter half of the 20th Century. Water voles have been lost from the majority of the British countryside due to the combined pressures of habitat loss and predation by invasive American mink. Our project seeks to counteract this process in the Upper Thames region by undertaking a number of water vole re-introductions. The release programme incorporates a field experiment designed to identify optimal site characteristics for successful water vole re-introduction.

What are we doing?

We will be re-introducing water voles to between 8 and 12 separate sites in the Upper Thames Valley over a two-year period from May 2004. Sites have been selected so that each comprises 1.6 km of suitable water vole habitat, and such that predatory American mink are not resident. We will continue to monitor for, and control the presence of, mink throughout the study. Forty water voles (20 males, 20 females) will be re-introduced to each site, and the populations monitored intensively using capture-mark-recapture techniques in each month following release. Previous WildCRU research has shown that the density of water vole populations is extremely sensitive to the amount of vegetation present at a site, since vegetation provides them with both food and shelter. We are incorporating an experiment into the release programme, designed to identify optimal site conditions for conducting water vole re-introductions. Half of the release sites will contain large amounts of vegetation, and half smaller quantities. Similarly, half of the sites will contain additional, artificial nesting sites, and half will not. This balanced experimental design will allow us to determine how levels of food abundance and nest site availability influence individual survival, body condition, breeding success and the rates at which water voles colonise surrounding habitat post-release.

How can you help?

The day-to-day running costs of this project have been funded by generous private donations; we would like to thank sincerely those individuals who have contributed, and without whom this work would not be possible. These running costs include the salary of a full-time Post-doctoral researcher and PIT tags for marking water voles etc. We are currently seeking vital funds for making one-off purchases of materials necessary for constructing the mink-monitoring rafts and water vole release pens (mainly plywood), and for supplying electric fencing which we can lend to landowners to facilitate correct grazing management throughout the study.

You can find out about the budget for this project by contacting us. See our contact details.

If you are interested in finding out more about the science involved in this project, we would be happy to send you further information.

WildCRU is part of the University of Oxford, a tax- exempt charity. To maximise tax benefits to both donors and WildCRU, please see Donations.

Principal funders
Private donors

Main Partners
BBO Wildlife Trust
FWAG
DEFRA