Ah, nuts: Crop failure to blame for fewer chipmunks
CONCORD – Where have all the chipmunks gone? This time of year those cute little striped rodents are usually scurrying all over the stone walls.
We asked friends and family in New Hampshire and Connecticut and everyone agreed they’ve seen few or no chipmunks this year. So we called New Hampshire Fish and Game and talked to wildlife biologist Kim Tuttle.
It turns out there are few chipmunks for the same reasons there was so much squirrel roadkill last fall. The squirrel apocalypse of 2018 was caused, first, by an abundant acorn crop in the fall of 2017, which meant many more squirrel babies, Tuttle said. The following fall there was a poor crop of beech nuts and of white and red acorns, especially red oak. What there was was scarfed up by deer and turkeys.
So hungry squirrels left the woods and spent a lot of time running around looking for food, including a lot of time on busy roadways where they met their inevitable ends. A quick Google search shows this same phenomenon has caused squirrels to do even weirder things, even swim across rivers in search of food.
That was then. This year, it’s chipmunks in search of food.
Chipmunks typically spend most of their time in their dens, including 15 hours a day sleeping. That’s a habit that’s good for their survival, because once they leave the safety of their dens they become prey to a host of animals: weasels, coyotes, bobcats, fox, snakes, fisher, martens, raccoons, red squirrels and raptors, including owls and hawks.
“The same phenomenon that knocked down” the squirrel population decimated the chipmunk population, Tuttle said, “a massive crop failure last fall that drove hundreds and hundreds of squirrels” to migrate away from their homes in search of food.
And the chipmunks, too, “just ran out of food,” she said, and their search for food, which can also include birds eggs and nestlings, made them more susceptible to predators.
Is all this a sign of an ecological apocalypse? Apparently not. The abundance and shortage of nuts is “just cyclical,” Tuttle said.
According to the National Wildlife Federation’s blog, however, climate change could be bad news for chipmunks, because as temperatures rise, they tend to hibernate less, again making them vulnerable to predators.
According to a National Wildlife Federation’s blog, chipmunks are basically tiny squirrels (1 to 5 ounces) that have adapted to burrowing. Other members of the squirrel family include woodchucks, prairie dogs, various ground squirrels and, of course, tree squirrels.
North America is home to 21 species and they produce one or two litters a year. Young are on their own within eight weeks.
Chipmunks prefer forested areas and can climb trees, shrubs and birdfeeders.
They eat various types of seeds as well as fungus, helping to spread the mycorrhizal fungi that live around tree roots and are critical to tree survival. Chipmunks also spread the seeds of trees and other plants.
Chipmunks aren’t particularly choosy about what they eat. Along with seeds and fungi they like grain, fruit, nuts, insects, worms, bird eggs and even nestling birds and baby mice. They probably don’t hunt for eggs and hatchlings, just eat them when they find them.
Wild chipmunks do vocalize. Kenneth Schmidt, a biologist at Texas Tech University who studies eastern chipmunks, recognizes three chipmunk calls, “the chip, the deeper chuck, and the startle call.” The last is an alarm that warns of impending danger. “Chipmunks will even make calls in a chorus composed of several of the little rodents-shades of Alvin. Simon and Theodore.”