By: Julie Barnes , Horticulture
Now aren’t they cute: Small, 5 to 6 inches long, weighing a mere 3 ounces, distinct tan and black stripes running along their backs, tan and brown lines encircling their eyes. Watching them dart from place to place brings to mind the cartoon antics of Disney’s Chip and Dale or the sounds and adventures of Alvin and the Chipmunks. Until I became a homeowner/gardener, chipmunks were quite charming. Now, the sight of dug up flower bulbs, countless holes, chomped up plants or fruits, has made me rethink this position.
The name chipmunk comes from the “chip, chip” sound this creature makes to communicate danger especially when you are in its territory. This small squirrel family member typically inhabits mature woodlands or woodlot edges where rocks or shrubs offer protection from predators. Similarly, suburban landscapes provide the cover that chipmunks need.
Even though they can climb trees, chipmunks or “ground squirrels” remain on the ground digging and building underground homes. They hide their burrows close to objects, buildings or sheltered areas such as stumps, wood or brush piles, basements, and garages. A burrow entrance is roughly 2 inches in diameter and is not encircled by obvious mounds of dirt because the chipmunk carries it in its cheek pouches and scatters it away from the burrow. The main tunnel extends 20 to 30 feet and can be quite complex incorporating a nesting chamber, food storage spaces, connecting side pockets and separate escape passageways.
The chipmunk’s diet consists of grains, nuts, berries, seeds, mushrooms, insects, and carrion. They also prey on young birds or bird eggs and to a gardener’s dismay flower bulbs, fruits, vegetables and seedlings. In spring, summer, and fall they are most active during the early morning and late afternoon busily gathering food. Extra amounts are stuffed in their cheek pouches similar to massive grocery bags that stretch 3X larger than the chipmunk’s head. Full loads of food are then carried back to the burrow for winter storage.
Chipmunks do not hibernate but become rather inactive during fall and winter subsisting on their stored food. That is why you may see them around when those days are warm and sunny. Mating season occurs twice a year, in early spring and again in early summer. Two to five young may be delivered after a 31-day gestation period, from April to May or from August to October becoming sexually mature within one year. Adults may live up to three years. Population densities of chipmunks are typically 2-4 animals per acre, but can become as high as 10 if sufficient food and cover are available. In large numbers, they can also cause structural damage by burrowing under patios, stairs, retention walls, or home foundations. Chipmunks are not protected by federal law, but are protected by the Pennsylvania Game Commission. Pennsylvania law allows landowners to take chipmunks when they are causing damage to property. So, what can you do?
Exclusion- Deter chipmunks from planting beds by installing 1⁄4-inch mesh hardware cloth and covering it with soil. Close openings so chipmunks cannot enter buildings with caulking materials.
Habitat Modification- Avoid connecting wooded areas to a home’s landscape. Know that wood piles or other debris can provide chipmunks with above ground protection. Locate bird feeders 15- 30 feet from buildings to lessen their attraction. Mow grass short around buildings to lessen shelter.
Repellents- Taste repellents labeled for use against squirrels can be used to protect flower bulbs, seeds, and foliage that are not intended for human consumption.
Trapping is an effective means of control around homes and gardens. Common rat snap-traps are used by some. Many prefer to use a live-catch wire mesh trap and transporting them next t several miles away so they don’t return. This is not really recommended. Another alternative for live- trapped chipmunks is to humanely euthanize them.