When Clement Clarke Moore (1779-1863) penned the words, "Twas the night before Christmas, when all through the house, Not a creature was stirring, not even a mouse," he wasn't thinking about what was going on outside that quiet house.
Right now, if the yard from a reader on the lower Hillside is any indication, all may be quiet and still in our houses insofar as rodents are concerned, but outside, things may be highway crazy. "Highway" as in the kind of system created by voles, which are tiny, mouse-like rodents.
Voles are at the bottom of the visible food web. They are eaten by all sorts of birds from ravens and magpies to owls and eagles. Weasels, foxes, coyotes, dogs and cats and even bears eat them. When present in large numbers, their predators' numbers increase. So do the populations of other animals that those same predators also eat, as voles seem to be preferred. When vole numbers are low, fewer predators are supported. Populations of voles can grow up to 50 times over the course of a few years and are highest every four or five years. Then their numbers crash.
Voles are around in the summer, though most gardeners never see them. When we do it is either for a fleeting moment as they are scurrying into a shallow burrow or when a dead one is found. They are vegetarians, and I suspect what people sometimes blame on cutworms may be caused by voles. Generally, however, they are not a pest in the summer.
Vole problems occur in the winter, when they burrow through the snow to get to food sources, safe from most predators. These food sources can include roots, bulbs and tree bark -- and therein lies one set of problems. The burrows develop into well traveled highways (voles memorize the system they create) and are often right at grass level, meaning the lawn grass gets chewed up. When the snow melts, the lawn is a mess.
How do you know if you have voles? Well, you do. The real question is: How do you know if you have large populations of them causing landscape damage? Our Hillside fellow gardener saw the tell-tale damage in his lawn when snow melted last weekend. If you have antlers outside, it is the voles that chew on them, so look for teeth marks. If your dog seems to be acting weird and digging in the snow, you have lots of them. Finally, you can look for entrances to burrows in the snow. Footprints and dung will be visible.
Then the issue becomes what, if anything, to do about voles in the yard. No one likes a torn-up lawn come spring or girdled trees. There are some remedies to try, but their effectiveness is questionable .
If you don't have an interested dog, start with traps. You will need several, and you will need to set them out for a week or so with bait but not "set" to trap. You want the voles to get used to them and your scent on them to dissipate. Put traps where there is a little cover. Apple slices and peanut butter are the preferred bait. You should release voles in woods away from lawns.
A second option is to tamp down snow around the perimeters of your lawns to confuse the voles. Remember, they memorize these routes and if you know those routes are there, you can tamp the snow down in the middle of the lawn as well.
For me, the real problem is the bark at the base of young trees and newly planted shrubs. If you can put protective coverings around them, do so. Aluminum foil works great. Tamp the snow down or remove it around new trees. Remember, the voles want that cover for protection.
Finally, you can use poisons to kill voles, but I am not in favor of these. The voles are too important to the food chain to poison. And you run the risk of another animal eating the dead vole and ingesting the poison.
Jeff Lowenfels is a member of the Garden Writers Hall of Fame. You can reach him at teamingwithmicrobes.com or by calling 274-5297 during "The Garden Party" radio show from 10 a.m. to noon Saturdays on KBYR AM-700.
