Tales from the river bank

Vole Position

The dramatic decline in the number of Britain's water voles has been well documented in recent years, but now there is hope for the animal's future, due in no small part to a pioneering repopulation scheme taking place in Herefordshire. Read on . . .

HEREFORDSHIRE is playing a leading role in efforts to halt the decline of the water vole, one of our most endearing and charismatic river inhabitants.

The summer saw the launch of a pilot scheme to reintroduce no fewer than 500 of the creatures to the River Monnow, on the county's border with Wales - a project which will form the blueprint for future water vole introduction schemes across the country.

The Game Conservancy Trust effort marked the final stage of the £1.1 million River Monnow Project, one of the largest catchment scale river habitat restoration projects in the UK, which saw more than 60 km of river habitat improvement, including coppicing trees and bank-side fencing, carried out on four tributaries of the Monnow (including the Dore) thus paving the way for the return of the water vole along 30km of river.

The Rural Development Service funded the Monnow Project from the outset and has now provided £80,000 additional funding from Defra for the reintroduction programme.

Dr Jonathan Reynolds, who is leading the project for The Game Conservancy Trust, said: "Water voles were once very common on the River Dore but like many other places in the UK they have disappeared in the past 20 years.

"Loss of suitable river habitat was one contributing factor; another major factor was predation by American mink, which was catastrophic for water voles."

Most people's only encounter with a water vole will probably have been via the pages of a book. Famously - and rather misnamedly - Ratty, in Kenneth Grahame's Wind in the Willows, was a water vole. The animals have, in the past, actually been called water rats - but vole is the correct term. Rats they are not.

Their decline in this country has been dramatic.

Nearly 70% of populations identified in a national survey in the late 1980s had been lost by the late 1990s.

As a consequence, water voles are now protected under the Wildlife and Countryside Act and are a Biodiversity Action Plan (BAP) species with a target of recovering their pre 1970s range by 2010.

Despite these special protection measures, water vole populations continue to be lost.

The crucial factor for the River Monnow effort was the removal of American mink from the river. Until recently, mink have proved difficult to control, mainly because they are often un-noticed until it is too late, but a novel device designed by the Trust - the GCT Mink Raft - revolutionised the effective control of the voracious predators.

Trust scientists designed rafts, which act as mink detectors and as trap sites, and which have been described as revolutionary for mink control and water vole conservation by the Environment Agency.

In another pilot project on the River Itchen, in Hampshire, mink rafts were laid over nine miles of river corridor. Initially the rafts, which measure 4ft x 2ft, were used in monitoring mode to determine where mink were present. Where mink were shown to be present, traps were added to the rafts to catch the animals.

Dr Reynolds said: "In a very short time we caught every breeding female mink in the area and, importantly, we could demonstrate that none were left.

"Satisfyingly, the water vole population has been very productive and successfully colonised suitable habitats."

Although simple, the rafts seemed 2 irresistible to mink and proved a very effective method of identifying their presence.

Moored along the riverbank, the rafts carry a wooden tunnel, which houses a small cartridge containing a permanently moist clay mixture in which animals leave their footprints and which the experts, in turn, were easily able to identify.

In the event of mink tracks the raft could be converted to trapping mode in minutes.

Primarily conceived as a research tool, the Game Conservancy Trust is now using it to develop appropriate strategies for the management of mink in a UK conservation context.

As the basis of mink population control, though, it already leads to improved effectiveness, lower cost, greater humaneness, and much lower involvement of non-target species.

So the Monnow was all set to welcome back the water vole. The aim, said Dr Reynolds, was to rebuild a population that was capable of surviving local flooding and other chance factors.

But getting the mink out of the way was only half the story.

The successful reintroduction of water voles also depends on specific skills in captive breeding and release of the animals.

However, there was expertise on hand, built up over 10 years and provided by the Derek Gow Consultancy, which is collaborating with the trust in the project.

Given the right conditions water voles breed very well in captivity and a good deal is already known about releasing techniques.

However, this is the first time a self-supporting population has been recreated on such a large scale.

Generally, however, thanks to initiatives like the Monnow project, the future's looking a lot more promising for the water vole.

Dr Reynolds explained: "The significance of this project is both its large scale and the fact that for the first time we are addressing all the key factors that have contributed to the loss of water voles.

"Our experience on the Monnow will prove invaluable to other conservation agencies and an important aim of the project is to provide training and demonstration opportunities that will guide reintroduction programmes elsewhere in the future."

Water Volves: Fact File

Water vole: Arvicola terrestris.

Distribution: Throughout the British Isles (except northern Scotland and Ireland), and Europe (except for southern parts of France, Portugal, Spain, Italy and Greece).

Also USSR, SW Canada and north western parts of North America.

Habitat: Rivers, canals, streams, ponds, lakes, marshes. Water voles can be found far from water, in woodland, meadows, crop fields and gardens.

Description: The water vole has a round blunt nose, long, glossy dark brown fur (some in Scotland have black fur), small ears and a shorter much rounder body than that of a rat. They weigh about 200g to 350g, and have a short, thin, furry tail - a rat's is hairless.

Water voles also possess flaps of skin in their ears which prevent water from entering.

Diet: Water voles are herbivores and feed on a huge variety of waterside vegetation.

They manage to consume 80% of their body weight each day.

Living space: The animals excavate extensive burrow systems into the banks of waterways which have sleeping/nest chambers at various levels in the steepest parts of the bank.

There is usually an underwater entrance to provide the animals, which are strong swimmers, with a safe route in and out. Entrances which are above the water line can often be identified by a 'lawn' of cropped grass around the hole.

Breeding: They usually have three or four litters a year, depending on the weather. In mild springs the first can be born in March or April.

Cold conditions can delay breeding until May or June. There are about five in a litter, which are born below ground in a nest made from suitable vegetation, usually grasses and rushes.

Although blind and hairless at birth, young water voles grow quickly, and are weaned at 14 days.

On average, water voles only live about five months in the wild.

Predators: Their most important ones are mink and stoats, although herons, barn owls, brown rats and pike are also known to take them.

A river revived

THE River Monnow was once one of the most productive trout rivers in England. However the last 30 years, in common with many other rivers, saw substantial declines in the wild trout and grayling populations, echoed in the reduction of several other important species such as otters, water voles and the native crayfish.

A number of factors has contributed to the decline but the most significant environmental impacts have been caused by livestock access, causing soil erosion and the growth of dense bank side tree cover, which prevents natural sunlight from reaching the river.

In 1999, a partnership, led by The Game Conservancy Trust, and supported by The Wild Trout Trust, the Salmon and Trout Association Trust, The Grayling Society, The Environment Agency in Wales and The Monnow Fisheries Association was formed to restore the river.

The partnership initiated a range of improvement measures aimed at not only reversing the decline of wild brown trout, grayling and other threatened wildlife, but also giving a major boost to the local economy through increased tourism from fishing interests.

Tasks carried out as part of the project included:

Coppicing. Coppicing of bank-side trees, particularly alders, allowed more light to reach the river, thus creating better habitats for insect species, fish and invertebrates through the new growth of low growing bankside vegetation and water weed.

Bankside fencing. To protect rivers and habitats from erosion and damage along the water's edge by trampling livestock.

Once fenced, bankside vegetation rapidly recovers providing cover for insects, butterflies, mammals and nesting birds.

Bankside revetments. An efficient and inexpensive means of trapping silt and restoring badly eroded banks.

Spawning gravel improvements. Trout require clean, silt-free gravel for successful egg survival.

Underlying the project has been a six-year scientific monitoring programme keeping track of fish populations, insects on which fish feed and changes in the population numbers of other wildlife.

Fish are stunned so they can be caught and their details recorded before being returned to the river.

Wildlife consultant Derek Gow with one of the

water voles at the launch of the release scheme on the River Monnow.

Looking at some of the improved habitat on the Monnow is Ian Lindsay of The Game Conservancy Trust. He was instrumental in setting up the improvement project and the water vole reintroductions.

A mink raft in situ.

Mink tracks captured in clay.