Small, furry and cute, the Eastern chipmunk is a common woodland critter in the state and it may well be coming to a vegetable patch near you. Gardeners in Maine are trying anything they can think of to keep the rodents from eating ripening crops in the wake of an explosion in the chipmunk population.
“I’m getting a lot of calls in regards to nuisance chipmunks right now where last year at this time I was getting maybe a handful of calls,” said Griffin Dill, integrated pest management specialist with University of Maine Cooperative Extension. “There are definitely more chipmunks on the landscape this summer.”
Chipmunks, easily recognized by their brown bodies with black and white stripes down the back, are omnivores that forage for grains, nuts, berries, seeds, mushrooms, insects and even salamanders on the forest floor or in the trees. But they are also more than happy to help themselves to a human supplied buffet of vegetables, fruit, seeds, seedlings and flower bulbs.
Ripening cucumbers are a primary target for the chipmunks right now, which makes sense, Dill said. The high water content of the cucumber makes it an attractive meal for the rodents during the recent hot and dry spell when natural sources of water can be hard to find.
“There have been a number of calls from people about chipmunks getting into their gardens,” Dill said. “I’ve also gotten calls from people telling me that chipmunks are causing some structural damage around foundations and particularly around steps and pathways.”
The small rodents cause the damage as they dig their underground burrows in which they live and store food.
“They can create quite a network of tunnels and cavities in those tunnels,” Dill said. “Most people think chipmunks are tree dwellers but in reality they stay close to the ground and make their homes under the ground.”
When it comes to controlling the pests, Dill said there are not many effective options.
One thing to try is preventing the chipmunks from getting to plants or trees in the first place.
“Generally when it comes to chipmunks what is recommended is exclusion to try to keep them away from bulbs and vegetables,” Dill said. “But that can be a time consuming and costly endeavor.”
On top of that, Dill said using mesh wire or anything else that the rodents can’t chew to cover or block access to plants is often not enough to stop chipmunks, which are nimble and adept climbers capable of getting up, under or around many obstacles in their way.
Commercial or homemade repellents are minimally effective in controlling chipmunks, according to Dill.
“What’s really left is trapping the chipmunks,” Dill said. “Lethal traps are an option but we recommend that you reach out to local game wardens first to make sure you are not running afoul of any laws or regulations.”
Dill discourages live trapping chipmunks to release back into the wild from your garden.
“Chipmunks are territorial, so it tends to not benefit the animal by taking it out of its home range and dropping it into a new habitat it’s not used to,” Dill said. “You are most likely dropping it into another chipmunk’s territory and that’s not good wildlife stewardship.”
This summer’s chipmunk boom is reminiscent of the boom in the Maine gray squirrel population the previous two summers, Dill said, which was followed by a natural decrease in the population this year.
Likewise, this summer’s population explosion of chipmunks will likely be followed by a natural crash in their numbers next year, Dill said.
“Chipmunks tend to be fairly territorial so for the most part their populations are within a particular landscape and those populations don’t get large enough to cause a lot of problems,” Dill said. “But as we are seeing this year, with even a little bit of a population explosion they are creating some issues.”