Water Vole Recovery Scheme: R. Chess

The water vole is Britain’s fastest declining mammal having declined by 90% in the last 30 years. The main reasons behind this decline are habitat loss and predation by American mink, an invasive non-native species introduced to the UK in the early 20^th century.

The R. Chess was found to support the last population of water voles found in the Chiltern National Landscape. In 2001 the Chilterns Chalk Streams Project (CCSP) working with local organisations, landowners and volunteers, undertook a survey of the river to determine the health of the population. The survey revealed a healthy population along much of the river. In 2003, following a series of sightings of mink along the river a repeat survey was carried out by the CCSP and the Berks, Bucks and Oxfordshire Wildlife Trust (BBOWT) which revealed that the population had dramatically declined by 97%.

In response CCSP, River Chess Association and BBOWT launched a Water Vole Recovery Scheme in 2004 which included a strategic programme of mink control and river habitat enhancement along with biennial quantitative surveys to monitor progress.