9 for 90: Water Vole

by Nick Acheson
Have you ever seen a vole? A remarkable number of people reading this will never have seen a vole; could not perhaps even say with certainty what a vole is. This is the more staggering because voles shall inherit the earth. They sit at the base of most terrestrial vertebrate foodchains and are super-abundant all around us. The UK population of the field or short-tailed vole was recently estimated to be 75,000,000, making it the commonest mammal in the country, and the only one more numerous than the human. This is great for barn owls and kestrels as these two species prey on field voles in huge numbers.

In Norfolk we also have two other vole species, the pretty chestnut-coloured bank vole which is often seen under bird feeders at nature reserves, and, around freshwater, the water vole. Until the recent, tentative reintroduction of the European beaver in Scotland, the water vole was our second-largest native rodent (after the red squirrel, now sadly extinct in Norfolk). Like the beaver it is a species of wetlands, living an amphibious life between land and water. Also like the beaver it has suffered a catastrophic decline. Beavers disappeared from the UK many hundreds of years ago, hunted out for their fur and gland secretions. By contrast the sharp decline of the water vole in the past thirty years has been precipitated by habitat loss, water contamination and predation by the non-native American mink.

Hilgay looking north west from SE corner, credit Hexcam

The bright-eyed, round-nosed, secretive water vole is the 9 for 90 species representing the Wissey Valley Living Landscape. Perhaps more than any other of our Living Landscapes, the Wissey Valley is about restoration and the recreation of habitat which had been lost. It has at its core two nature reserves which Norfolk Wildlife Trust and partners have carved from surrounding farmland and – by just adding water – are nurturing back to wildness and biological diversity.

It has taken a little more than just adding water of course. In fact, the creation of the Hilgay and Methwold nature reserves has taken massive engineering, planning, thought and funding, the last largely from the Environment Agency, in mitigation, under the EU Habitats Directive, for the managed retreat from sea defences at Cley and Salthouse and along the Suffolk coast. The recreation of reedbed and grazing marsh at Hillgay and Methwold has been a tremendous success, with many species of wetland bird, plant and invertebrate moving back to the site and more predicted to return soon.

But what of the water vole? Why have we chosen it to represent the Wissey Valley in Norfolk Wildlife Trust’s 9 for 90, nine species in celebration of our 90 years of nature conservation in the county? Water voles are a flagship species for the Wissey Valley Living Landscape. They have held their own in the network of ditches which drain the land here, despite the depredation of mink. What’s more, both on NWT reserves and on neighbouring farms where patches of wetland have been recreated, there is greatly more habitat

Perhaps more than any other of our Living Landscapes, the Wissey Valley is about restoration and the recreation of habitat which had been lost

available to water voles in the Wissey today. Water voles have been specifically favoured on NWT’s two new reserves by re-flooding ditches and drains which had been dry, and by re-profiling them to have one steep bank for burrowing and another sloping bank covered in succulent wetland vegetation to eat.

In addition, as controversial as the subject of predator control often is, water voles are protected on NWT reserves by a careful programme of monitoring both voles and their pernicious predator the introduced American mink. Where mink are found to be active and affecting water voles they are humanely removed.

A secure future for the water vole is not just good for them. Habitat for water voles is also great for otters, little grebes, water rails, bitterns and many other wetland species. And a healthy population of water voles means plentiful food for native predators including marsh harriers and grey herons.

If you wish to see a water vole, in the Wissey Valley or elsewhere in Norfolk, you need to enter this reclusive animal’s life. Start by visiting the right habitat. Rivers and dykes through fen and grazing marsh have traditionally been considered good habitat for water voles. Increasingly it is also believed that pools in reedbeds may be optimal habitat as these are less easily patrolled, in transects up and down banks, by hungry mink.

Water vole, photo by Jamie Hall

Signs that you may be in water vole country are subtle but distinctive. Water voles build extensive burrows in the banks of rivers and dykes, with nest chambers at various levels to ensure safety from flooding. Many of the mouths of their burrows are beneath water level, providing protection from predators. However sure signs of the presence of water voles include small lawns of closely-cropped grass on the riverbank where the rodents have grazed, piles of neatly nibbled grass stems, and latrines of tiny, dark, cigar-shaped droppings.

If you startle a water vole on the bank you will most likely hear a loud plop as the animal jumps into the water below. You may then see a V-shaped ripple as it swims away, its little legs whirring in doggy-paddle beneath the water. With patience, by sitting along a riverbank where you know water voles live, you could see one of these plump, dark-furred, little animals come to the bank to graze. The wait will be wholly worthwhile.

That’s 1,000 words on the water vole and not a single mention of the too-often-quoted nugget that Kenneth Grahame’s Ratty was in fact, a water vole. The water vole needs no celebrity look-alike to be appealing and intriguing. It is one of our most charming native mammals and one which is a deserving representative of the Wissey Valley Living Landscape in our 9 for 90: a landscape coming back to life represented by a delightful species whose recovery we hold in our hands.

Currently there is no visitor access to the reserves as construction work is ongoing. Views over the Hilgay site can be obtained from the bridleway along the southern bank of the River Wissey. Please park sensibly in Hilgay village and walk east along Woodhall Road and Sandy Lane to reach the bridleway network.