River Chess Association

Water vole numbers along the River Chess have increased significantly since 2009, according to the results of the latest survey by the Chilterns Chalk Streams Project (CCSP) and the Berks, Bucks and Oxon Wildlife Trust (BBOWT).

The water vole population on the Chess plummeted by 97% between 2001 and 2003 because of predation by invasive, North American mink that had become established along the river. As a result, BBOWT and the CCSP, working with landowners, set up a water vole recovery scheme on the river in 2004 and water vole numbers have subsequently recovered well. By 2009 the population had increased to 87% of its 2001 size. The 2011 survey has revealed even better news: “It’s fantastic to discover that the water vole population on the River Chess has fully recovered to its 2001 level”, says Julia Lofthouse, Water Vole Recovery Project Officer at BBOWT. 

This striking success has been a result of combining a catchment-wide mink control scheme with a series of projects to improve riverbank habitat for voles, reducing predation and helping water voles to colonise new areas of the river. “This is a brilliant result both for water voles and for all those who have worked so hard on the project.” says Allen Beechey, Chilterns Chalk Streams Project Officer, “However, it is important for us not to become complacent, as mink continue to be found along the river, with at least one being trapped in the last year and one being seen as recently as last July.  It is vital that landowners remain vigilant to ensure that we do not see a reversal of fortune for the river’s water voles.”

The RCA is delighted at this conservation success story, but supports the need for vigilance in monitoring for mink. If you have seen mink, or evidence of mink, in the Chess catchment, please let us know by getting in touch with us via the Contact Us page. 

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