Wildlife - Derbyshire’s two smallest voles

Bank Vole

Bank Vole - Credit: Archant

Paul Hobson looks into the lives of two tiny creatures

Bank vole in autumn woodland

Bank vole in autumn woodland - Credit: Archant

I have always been fascinated by some people’s irrational fear of wildlife. I can see why a fear of snakes could be a good thing because some are poisonous. I can understand why we took a dislike to house mice because they would eat our food and the skittering of tiny toe nails on wooden floors at night could keep you awake (though I can’t understand why we would be frightened of them).

Today mice in our centrally heated, hermetically sealed homes are quite a rare thing and when one does intrude into our castle it is more likely to be a wood mouse from the garden. Most people can’t distinguish between a vole and a mouse. Many, when they see a water vole for the first time are convinced it is a rat. When I run wildlife photography days I sometimes bring a few harvest mice along. Initially there are a few ‘I can’t stand mice’ comments but almost everyone I have met when viewing harvest mice for the first time falls rapidly in love with them. They are that cute.

The best way to learn about our voles and wood mice is to attend a live mammal trapping session (often run by Wildlife Trusts and nature groups). This should quickly dispel any irrational fear of these lovely little mammals.

Derbyshire has three vole species as resident – the water, bank and field (sometimes called short-tailed) voles. The last two are very common – in fact there are probably more bank voles in Britain than any other mammal – but they are often confused with each other; they are very similar in size and both have smallish eyes. Generally, however, bank voles are more of a russet colour with noticeable ears and a mid-length tail. The field vole is greyer with smaller ears – often they are not even noticeable – and a short tail. If the furry critter has a long tail, big eyes and jumps like a mini-kangaroo it’s almost certainly a wood mouse.

Field vole

Field vole - Credit: Archant

Bank voles and wood mice can, and often do, live in gardens, even in urban areas. Field voles are less likely to be seen unless your garden backs onto a rough grassy area. Bank voles tend to be found in areas such as woodlands, woody gardens, parks and hedgerows. Field voles prefer areas of rank grassland such as old meadows, unploughed fields and areas of grassy moorland.

Both voles are surveyed by using a number of methods. One is to use live mammal traps, often called longworth mammal traps. These do the animal no harm and provide it with a warm bed and nice supper overnight. When I was at university, we did a project on the bank vole and wood mouse populations of several small woods in Derbyshire and would set the traps and monitor them every four hours. We marked any caught voles by clipping a small bit of fur from their side which didn’t harm or hurt the animals at all. If we trapped in the same area too often we would regularly catch the same vole. We called these trap-happy because we reckoned that as soon as it was released it waited ten minutes than sprinted back into the trap. The bonus of a good meal clearly outweighed the handling by a caring human!

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The other way to survey voles is to collect owl and kestrel pellets. Barn, tawny, long and short-eared owls plus kestrels prey heavily on small mammals. They often swallow the animal whole or in a few big bits. They digest the nutritious meat but regurgitate the fur and larger bones as a pellet. By collecting these and soaking them in water it is easy to separate out small skulls and jaw bones which can be identified. By knowing where the owl hunts, which in the case of tawnies is mainly in woods and large gardens, barn owls in grassy fields and short-eared owls on moorland, we can easily make good assumptions as to the type of small mammals living there.

If you become one of the growing band of wildlife watchers and gardeners who fall in love with these charming animals it is easy to set up a project to watch them. If you run a bird table you will probably find bank voles and wood mice (if they are in your garden) snaffling up any spilt seeds. They are very quick learners and opportunistic feeders. A few years ago I ran a wooden tunnel from the bottom of my bird table to my living room window. Then I built a small box with three sides, top and bottom, a lid I could open and a hole for the tunnel. I pushed the open side of the box against the glass window. By keeping the box stocked with apple bits, raisins and mixed seeds I provided a tasty snack for the voles and mice and it wasn’t long before they came to dine in my box. I could then sit in the comfort of my living room and watch these delightful small animals whenever I wanted.

Field vole

Field vole - Credit: Archant