Q What attracts voles to gardens?
A Gardens are ideal habitats for these small mammals as they provide plenty of cover and a wide range of food sources. Sometimes, however, they come into conflict with gardeners when food supplies consist of highly valued plants, seeds and bulbs. When populations peak and food runs short, voles are more likely to become a nuisance in the garden.
Caption: Voles are usually only seen at night
Q Can you tell me more about these animals?
A Voles are small mammals that sometimes feed on garden plants. They are shy nocturnal animals, so there could be more of them in your garden than you suspect. You are most likely to see them when they’re brought into the house by cats. Rats and house mice are seldom a problem in gardens, although rats may take up residence in compost bins and garden sheds. Dealing with rats is usually a job for the professional – ask your council for help. Voles commonly live in gardens, where their vegetarian diet can cause problems for gardeners. For most of the year their numbers tend to remain low. However, in autumn they can build up high populations and cause a great deal of damage into early winter.
Q Could I mistake them for anything else?
A Shrews, unlike voles, are predators which destroy many insects and slugs and so are helpful to gardeners. They have a thin, pointy snout, almost invisible ears, and relatively short tails. They are very small and are mainly active at night.
Q What types of voles am I likely to see in my garden?
A The following can all be found in gardens in this country:
Short-tailed vole (Microtus agrestis) Unlike mice, voles have short noses and ears. The tail is one-third of the length of the rest of the vole. They are a greyish-brown colour. They are active in the day but are seldom seen and less active in the winter. Short-tailed voles are 9.5-13.5cm long and breed all summer. As many as one per square metre has been recorded. They live in rough grass, making above-ground domed nests and tunnels in the grass. They feed mainly on grass shoots but also eat other plant shoots. Fibrous straw mulches also make ideal habitats for voles to thrive in.
Bank vole (Clethrionomys glareolus) These live in banks, hedges and around shrubs. They’re 8-11cm long with reddish-brown fur and a light underside. They feed on seeds and fruit, living in similar nests and runs to the short-tailed vole.
Water vole (Arvicola amphibius) This is much bigger, at 15-20cm, and less common than the others, with dark brown fur, and brown/grey underparts. It lives around water, including garden ponds, feeding mainly on plants. Although sometimes known as water rats, water voles have blunter heads and smaller tails, and do not spread diseases or cause the same damage as land rats.
Q What damage is caused by voles?
A Seeds are often eaten by voles. They will invade the greenhouse to carry off newly sown seeds from seed trays. The seeds of trees are also often eaten by voles, but this is usually helpful to gardeners, as it prevents large numbers of unwanted seedlings from appearing.
Bulbs, corms and tubers may be consumed by bank voles, especially newly planted ones. They like tulips and crocuses in the autumn.
Fruit and vegetables may be taken by voles. Voles often feed on brassicas and will strip Brussels sprouts from the stems. They also enjoy eating roots – beetroot and stored potatoes, for example. Soft fruit is a favourite food, especially strawberries. Bank voles will even climb trees for fruit and berries.
Bark may be stripped by mice and voles at ground level. Voles are particularly well known for this, often concentrating on one particular species of tree. Beech trees are the usual favourites. Bank voles can strip bark higher up, with damage occurring at 0.6-1.8m from the ground. Shrubs and herbaceous plants are also attacked by both animals.
Banks can be undermined by the burrows of these animals, especially those of the water vole which are around ponds and streams. However water voles are rare and such damage is not common.
Q Don't voles do some good too?
A They are important food for owls, foxes and other wildlife, so unless they are troublesome, they should be left alone. Voles also eat insects and weed seeds; in this respect, they are helpful to gardeners.
Q What can I do to deter them?
A Seeds and bulbs can be started off indoors in pots. Fine mesh wire netting (6.5mm) and a sound concrete floor can exclude them from the greenhouse.
Outside, wire netting placed over buried bulbs and seeds can protect them. It can also be wrapped around tree stems and buried slightly to guard tree and shrub stems from gnawing.
Where pond banks are being undermined, laying wire netting on the bank should exclude the voles and protect the bank.
In extreme cases, trapping can be carried out. Bait the traps with apple or carrot for voles. Voles are more difficult to trap than mice. Cover traps with a cloche or propped-up seed trays so birds and pets are not hurt by accident.
Live-capture traps, where the animals are taken alive, can also be used. The traps must be checked every day, and trapping has to be carried on for a long period, as empty sites are soon recolonised by voles moving in from elsewhere. For this method to be effective, you have to release the trapped animals at least half a mile away, or there is a good chance they will make their way back.
Q Can I poison them?
A No. Poisoning in the garden could present far too high a risk to pets and wildlife. Careful trapping and preventative measures should be enough to limit damage.
Q Are there dressings I can use to protect my seeds and bulbs?
A The old remedies involving poisons like lead are no longer allowed and, in any case, are very risky for the gardener to use. There are no safe, effective modern substitutes.
Q Can these animals be discouraged?
A Mowing long grass and cutting back vegetation will deny them cover and reduce the damage caused by voles. Avoid using cut grass and straw as a mulch, as this provides an ideal habitat for voles.