Biodiversity
Water Voles
The water vole was once a common sight along the banks of rivers, streams, canals, lakes and ponds in Britain. However, as a result of habitat loss and degradation and predation by the American mink they have suffered a catastrophic decline; the most serious decline of any wild mammal in Britain in the last 100 years.
Key Facts
- Ratty in Kenneth Grahame's book, The Wind in the Willows, was not a rat at all but a water vole.
- The water vole is a vegetarian rodent living on the banks of rivers, streams, canals, reedbeds and other wetlands. It was once commonly found throughout the UK but has been suffering a long-term decline since the 1900s.
- Between 1990 and 1995 water vole populations on the River Thames catchment declined from 72% to 23% site occupancy, and, in some parts of the country they have become extinct.
- The American mink, introduced to the UK for fur farming, has through accidental and deliberate releases, successfully colonised much of the British countryside and is still spreading. Mink have a devastating impact upon water voles and are capable of completely eradicating entire colonies from large sections of river within a single breeding season.
- In April 2008 the water vole became subject to increased legal protection and is now fully covered by the Wildlife and Countryside Act (1981).
Water voles
The water vole was once a common sight along the banks of rivers, streams, canals, lakes and ponds in Britain. However, as a result of habitat loss and degradation and predation by the American mink they have suffered a catastrophic decline; the most serious decline of any wild mammal in Britain in the last 100 years.
Considerable effort by the Cotswold Water Park Society, local landowners and volunteers, is resulting in an increase in the range of water voles throughout the Cotswold Water Park, which is very encouraging news.
Water vole and mink
Predation on water voles by American mink has been and continues to be a major contributing factor in their decline. Female and juvenile mink are small enough to be able to fit inside water vole burrows and catch them underground, and a single female mink feeding her young is capable of hunting out every water vole in a colony.
In partnership with the Environment Agency, Natural England, The Wiltshire Wildlife Trust Water Vole Recovery Project, Gloucestershire Wildlife Trust and many other groups, the Cotswold Water Park Society has established a programme of coordinated mink control in the area. The aim is to significantly reduce mink populations in the Cotswold Water Park and surrounding area to enable the water vole to recover.
Results demonstrate that this work has already been very successful, enabling a quick and widespread recovery of water vole populations across the Cotswold Water Park. Between 2008 and 2010 the watercourses in the western section of the Cotswold Water Park were surveyed for the presence of water voles and the findings were compared to those from previous surveys in 2004. The findings were encouraging with water vole populations increasing in range or remaining stable.
Good places to see water voles today include the River Thames between Neighbridge and Ashton Keynes, the River Churn near South Cerney and the River Coln in Fairford.
Download Water Vole recovery programme report
For further information please contact Gareth Harris, Biodiversity Field Officer on 01793 752413 or email gareth.harris@waterpark.org.
Page updated June 2010
