Water vole hotspots in Wiltshire01/12/2007 00:00:00 For the first time the Wiltshire Wildlife Trust has been able to produce a snapshot of the state of the water vole in Wiltshire, and it turns out that five of our rivers contain hotspots for Britain’s most endangered mammal.
Thanks to the efforts of 60 volunteers who went out surveying the waterways over the summer, the Trust has found that the Rivers Kennet, the Salisbury and Bristol Avon, the Wylye, the Nadder plus the Kennet and Avon Canal have colonies of the chestnut brown creatures.
The volunteers found water voles at 23 out of the 25 sites they surveyed and by using this information together with records collected over the past five years, the Trust has been able to designate local key areas representing important water vole colonies. The whole of the River Nadder has been identified as a local key area for voles because there are records from every 2km of its length.
‘This information gives us a clearer picture of where we must target our work to help voles recover from the disastrous population crash they have suffered in recent years’ says the Trust’ Water Vole Recovery Project Officer Beth Nightingale.
‘The habitat in these key areas is quite good, but some locations need altered management such as fencing off river banks to protect them from livestock trampling and overgrazing.’
Most, if not all, of Wiltshire’s rivers would have been home to water voles at one time. One of their favoured habitats is the chalk stream with its clear waters and vigorous plant communities, including water crowfoot and watercress. But numbers in Wiltshire have dropped by 30% over the last decade.
Despite this, the county is still a stronghold of the vole compared to the rest of the nation, where populations have declined by 94% over the same period, making it not only our fastest declining mammal, but also one of our rarest. The two main causes are habitat loss and predation by the American Mink.
‘There is no way that individuals at the Trust can survey all the waterways in Wiltshire, so the information provided by the volunteers is invaluable in helping us map the colonies so that we can work to link them together. We’d like to give a huge thank you to our dedicated band of volunteers,’ says Beth.
Voles tend to group together in winter, and string out as individuals over the summer. The size of a vole’s territory depends on the quality of habitat. If there is plenty of vegetation for food, good banks for burrows and clean water, they can live within small territories of only 10 to 50 metre lengths of riverbank.
The Local Key Areas in Wiltshire include two sites on the Kennet around Silbury Hill, and downstream of Mildenhall; two on the Kennet and Avon Canal around Semington and Pewsey; one near Melksham on the Bristol Avon and one near Malmesbury. There are two on the Salisbury Avon, and large sections of the River Wylye as well as the River Nadder. These are not official designations and will hopefully expand over time.
The Water Vole Recovery project is supported by Mammals Trust UK, the Environment Agency, North Wessex Downs AONB, Cranbourne Chase and West Wiltshire Downs AONB, Natural England, the Arbib Foundation and various charitable trusts.