Outsmarting Wildlife Pests in Your Yard

By Elizabeth Cornell Fake, Fairfax Master Gardener
What happened to my tulip bulbs? Who ate the hostas to nubs? Where did my vegetables go? Fairfax County residents are continually asking questions like these at local plant clinics staffed by master gardeners. At a recent training session for Fairfax County master gardeners, a wildlife expert provided some ideas on how to minimize yard and garden destruction caused by wildlife. What follows is a summary of what Tony Bulmer, a naturalist/historian senior interpreter at the Ellanor C. Lawrence Park in Centreville, had to say.

Bulmer began with a description of the environmental conditions that allow backyard wildlife to thrive: food, water and shelter. If you have all three, you will have wildlife visitors. A bird feeder is a certain attractor for a wildlife nuisance — birdseed is irresistible to many animals. Those who insist on feeding their pets outside can expect to have wildlife visitors as well. If you have fruit or nut trees and leave fallen fruit on the ground, say hello to all manner of hungry varmints. Next, water in the form of sprinklers, birdbaths, fountains and ponds provides sustenance for many kinds of furry friends and insects. Excessive groundcovers provide sheltered space for wildlife and a protected place to dig dens and burrows. Any kind of covered space from fallen trees to rotting sheds allows animals to flourish. Do not be deceived; your compost bin also provides a welcome shelter for our furry friends. In short, Bulmer recommended you think twice about putting up a bird feeder or birdbath; feed your cats and dogs inside; and keep your property free of rotting fruit, high grass, invasive ground covers and wooden debris.

Bulmer talked at length about unprotected species and the option to shoot unwanted wildlife. There are strict firearms restrictions in Fairfax County. A private property owner must have a 20-acre or larger property to legally discharge a firearm. Bulmer also discussed the danger of using common poisons to eradicate vermin. Although different kinds of rat poison shaped as “bait chunks” can be very effective to combat rodents, there is always the danger pets or children will eat them too. He followed with comments on animal traps and how to use them. Peanut butter and apples make good bait to attract most critters, so catching them isn’t a problem. The difficulty lies in what to do with them after they are caught. For those who cannot bear the thought of euthanizing a wild animal, be aware it is illegal in Fairfax County to relocate a trapped animal from one part of the county to another. Do not, for example, relocate a trapped animal to a county park.

Bulmer described other wildlife deterrents that seem more humane. They include everything from installing backyard spotlights, spreading human hair over flower beds, using homemade sprays made of hot peppers or castor oil, and planting noxious plants known to be offensive to wildlife. If opossums or raccoons are bothersome, fill tin cans with old rags soaked in ammonia, and locate them where the animals live. They won’t stay around long. Other deterrents include use of scarecrow devices, such as plastic pinwheels, and a closed-loop tape recording of human sounds played at night. Many of these deterrents encourage our wildlife friends to find a new home, and they will leave. (Note that none of these homemade solutions are included in the Virginia Cooperative Extension’s official Pest Management Guide, so master gardeners cannot vouch for their effectiveness.)

Of all species, we are most likely to contend with the meadow vole (microtus pennsylvanicus), which is the most prolific mammal living in our local environment. Also known as the field mouse, their aggressive reproductive cycle can produce up to 22 litters a year of three to six babies. One square-acre of ground will support up to 8,000 voles and their characteristic surface runways. Voles are herbivores that nosh on green plants, bark and grasses, keeping the forest contained. They also eat anything in their path, including bulbs, tubers and roots, which might explain why your tulips and lilies were a no-show in a given year. Low on the food chain, voles provide a tasty dinner for their predators, which include snakes, red foxes, owls, hawks and even the family cat.

To help control voles, make your yard inhospitable by keeping the grass cut and gardens trimmed and weeded; eliminate excessive mulch, which serves as a vole runway cover; and fence your garden and trees. A simple homemade fence can protect shrubs and trees from vole damage. Use a hardware-cloth collar made with quarter-inch wire mesh around the bottom of the tree. The collar should extend from 6 inches under the soil to 12 inches above. For gardens, use the same kind of quarter-inch hardware cloth to fence around the perimeter of the garden bed with at least 10 inches of the fence buried underground and 12 inches above.

Bulmer surveyed the many types of wildlife that are currently active in Fairfax County. Some of the more interesting are presented below, along with coping strategies:

Eastern chipmunk
After voles, chipmunks are the most damaging critters to our gardens. They eat everything in their path and burrow extensively. As they cache food for future use, you can stop them by plugging the holes of their burrows. If you have a bird feeder, you will have chipmunks.

Eastern gray squirrels
Eastern gray squirrels vie with chipmunks and voles as the most destructive small mammals to inhabit our yards. They are omnivores who kill and eat the birds attracted to bird feeders. They gnaw on wood to sharpen their teeth and are strong, powerful diggers. Squirrels provide food for animals higher up on the food chain such as red-tailed hawks and red foxes. They are not protected under law as a native species.

Eastern moles
Moles are often confused with voles because of a similar tunneling behavior. Although we rarely see moles, they build highways and burrows across our beautiful lawns, which terminate in unsightly molehills. Moles are meat-eaters, surviving on earthworms, slugs, snails, centipedes, larval and adult insects, scarab beetle grubs and ants. They are active 24 hours a day so it may seem they are more of a problem than they are because of their constant motion. When the food supply is running low, moles will abandon the current site, move to another place, and start new tunnels and burrows. Their natural predators include owls, foxes, coyotes and dogs. (The Virginia Cooperative Extension’s Pest Management Guide recommends trapping them.)

Rabbits
Rabbits build long tunnels that are destructive to your lawn and bushy shrubs. They are also prolific, producing three to seven litters of babies per year, which often become tidbits for higher food-chain predators, such as raccoons, foxes, hawks, owls, crows, snakes, opossum, cats and dogs. Rabbits are herbivores, and you can count on them decimating your vegetable garden. Plugging up their burrows gives you a fighting chance. Repellants applied frequently have some effectiveness. Fencing also helps, but you have to commit to building a rabbit-proof fence extending at least 12 inches underground to prevent the rabbits from digging underneath.

Coyotes
Yes, we do have coyotes, and they are getting bolder with their incursions into our neighborhoods. They have no natural predators, as yet, so they are at the top of the wildlife food chain. Having a birdfeeder and feeding pets outside are likely ways to attract them. They hunt in pairs and eat small mammals including house cats. They are not protected under law as native species.

Red foxes
Red foxes are not native to Northern Virginia but have adapted well to the conditions here and are becoming more prolific. They provide good rodent control but can be a danger to pets. Because of warmer winter temperatures, they now reproduce up to twice a year. To discourage them, remove sources of water. They are not protected under law as a native species.

Skunks
Skunks belong to the weasel family and are the least destructive of small mammals. They are shortsighted, move slowly, and use their scent for protection. They survive on grubs that flourish in a wet environment. As soon as the soil dries out, the grubs disappear along with the skunks. Fencing helps deter skunks from taking up residence in your yard.

Raccoons
Raccoons are one of the most adaptable and intelligent of backyard intruders. They travel widely and roam a large territory. They are nocturnal and good at climbing. Fiercely maternal, the females will claw and bite through a wall to get to their babies. Raccoons can transmit rabies through biting and scratching. Avoid building a dog door if you want to deter raccoons from entering your house.

For those who become exasperated with damage caused by backyard wildlife, it is a good idea to consult with local and state authorities about the problem. The laws and regulations are constantly changing, and the status of protected versus unprotected species can be unclear. Hiring a professional exterminator is always a good idea because they have the equipment and certifications to remove unwanted pests legally with the desired results.

Resources
Nuisance and Problem Wildlife, Virginia Department of Game and Inland Fisheries
Other Animals, Vertebrates as Pests, Virginia Tech