Copyright: Rob Strachan
Once common and widespread, this species has suffered a dramatic decline in both numbers and distribution. Numbers have fallen by an estimated 89% since 1939 (1). This decline continues and is the most significant for any British mammal, with a projected possible extinction early this century.
The water vole is the largest British vole. Despite its name, it is not particularly well-adapted to an aquatic existence, as its fur is prone to waterlogging and it lacks webbed feet. However it swims and dives well, an important trait that helps it avoid many predators.
Water voles live in colonies extending along watercourses. The voles construct complicated tunnel systems in the banks with entrances both above and below the waterline.
Water voles are herbivorous, feeding largely on the stems and leaves of waterside plants.
Water voles seem to prefer slow-moving watercourses less than 3 m wide and around 1 m deep, with lush bankside vegetation and no extreme water level fluctuations. Canals, water meadows and ponds are also used. In urban situations sub-optimal areas are often inhabited, where the lack of predators can compensate for reduced bankside cover.
Main Habitat(s): Rivers and streams; canals; farmland ditches, ponds
The pre-breeding British population is currently estimated at 1.2 million. The water vole is a Priority Species in the UK BAP because of its declining population. In 1998 the species received some legal protection in Schedule 5 of the Wildlife and Countryside Act 1981. Section 9 (Part 4) now protects its places of shelter, but not the animals themselves.
Water voles are found in all the counties of North West England. They are still widespread and locally common in Cheshire. Merseyside is a stronghold. They are, however, rare in Cumbria. Elsewhere in the region their status is largely unknown.
There have been no published surveys of the species in Lancashire. Anecdotal evidence suggests that the species was common and widespread in many parts of the county but has declined dramatically over the last three decades.
Martin Mere, Mere Sands Wood and Leighton Moss are all known to hold breeding populations. A 1999 survey of north Merseyside (2) revealed good populations in several areas adjacent to West Lancashire. In West Lancashire itself unpublished data (3) from a survey of 54 sites show that 42 (78%) had signs of water voles presence indicating that this district may be particularly important for this species.
Current factors affecting the Species
Loss, fragmentation and degradation of habitats are thought to be the most important reasons for decline (4). Suitable waterside habitats have been lost as a result of in situ development, engineering works and the inappropriate management of bankside vegetation (the most notable problems being the timing and severity of cutting). These factors destroy actual or potential breeding areas, resting places and refuges. Fragmentation causes the loss of interconnecting river corridor habitats and suitable ditches.
Predation by feral mink is known to have caused local declines in south west Lancashire, most notably at Martin Mere. Mink appear to be more efficient predators of water voles than their native predators and have undoubtedly caused the extinction of vulnerable populations. However, mink are unlikely to have caused declines of water voles without other factors already putting the voles at risk (4).
The inadvertent poisoning of water voles by rodenticides is an issue in many urban fringe areas (8). The target species is brown rat. Again, the extent of this problem in Lancashire is unknown.
Current Action / Mechanisms
The Vincent Wildlife Trust carried out national surveys in 1989-90 and in 1997-98 (1). There is on-going research by the Environment Agency (EA) and the Oxford University Wildlife Conservation Unit (Oxford WildCRU) into water vole ecology. The water vole is one of the focal species of the Wildlife Trusts.
Nationally, action is co-ordinated by the UK Water Vole Steering Group; chaired by the EA. The Steering Group produced a national Species Action Plan in 1997. The Oxford WildCRU has produced three publications on water vole conservation, with backing from the EA and English Nature (EN) (3,4,5). EN has published and distributed guidance for planners and developers in 1999 following the species gaining legal protection under Schedule 5 of the Wildlife and Countryside Act 1981: Section 9 (Part 4) (6).
Locally, EA are reviewing their water course management regimes where water voles are known to occur.
EA and the Wildlife Trust (WT) have nominated staff to respond to enquiries. These staff meet at least three times a year to coordinate surveys and manage any issues arising from them.
A water vole survey of Merseyside and Lancashire was started by the Wildlife Trust in 1999 under the guidance of the partnership, with part-funding from EA, Lancashire County Council and others. The Alt 2000 River Valley Initiative has played a major role in the survey of the Alt catchment. Other RVIs in the Mersey Basin Campaign Area may be able to assist in future survey work.
The survey work involves training volunteers to identify water vole signs and asking them to survey their local area. Survey results present opportunities for press releases to raise the species’ profile.
Under the present Biological Heritage Sites Guidelines sites may qualify (under Guideline Ma1) due to the presence of water vole populations.
Objectives, targets and proposed actions for water vole in Lancashire
References & additional reading:
1. Strachan, C., Strachan, R. and Jefferies, D.J. (2000) Preliminary Report on the Changes in the Water Vole Population of Britain as Shown by the National Surveys of 1989-1990 and 1996-1998. The Vincent Wildlife Trust, London.
2. Neale, D. (1999) North Merseyside and West Lancashire Water Vole Survey 1999. Internal Report for The Environment Agency and Lancashire Wildlife Trust, (LWT). Preston.
3. Abbas, N. & Charles, K. (2001) Lancashire, Greater Manchester and North Merseyside Water Vole Survey. 1999-2000. Interim Report. The Wildlife Trust for Lancashire, Manchester and North Merseyside, Preston.
4. Strachan, R. (1998) Water Vole Conservation Handbook. English Nature/Environment Agency/ Wildlife Conservation Research Unit, Peterborough/Reading/Oxford.
5. Strachan, R. (1997) Water Voles. Whittet Books, London.
6. Macdonald, D. & Strachan, R. (1999) The Mink and the Water Vole – Analyses for Conservation. Wildlife Conservation Research Unit & Environment Agency, Oxford.
7. English Nature (1999) Guide to developers on water voles.
8. UK Biodiversity Steering Group (1995) Biodiversity: The UK Steering Group Report. Volume 2: Action Plans. HMSO, London.
Date: April 2001.