The small, striped mammal known as the chipmunk is a common sight across North America, constantly darting through forest undergrowth and suburban yards. These active creatures belong to the squirrel family (Sciuridae) and are classified as omnivores. Their diet naturally incorporates both plant and animal matter.
Primary Natural Food Sources
The bulk of a chipmunk’s wild diet consists of plant-based items gathered from the forest floor and low vegetation. Seeds are a major food source, including those from various trees like pines, as well as smaller grass seeds and grain kernels found in open areas. They are particularly drawn to mast crops, which are the nuts produced by hardwood trees.
Acorns from oak trees are a particularly favored item, along with beech nuts and hickory nuts. Chipmunks often climb trees to access these nuts directly before they fall, despite primarily being ground dwellers.
In addition to seeds and nuts, chipmunks consume a wide variety of wild fruits and berries when they are in season. They also actively seek out fungi, including various mushrooms and subterranean truffles. By consuming truffles, they play a role in dispersing the spores of these fungi, which are often involved in symbiotic relationships with tree roots.
The Role of Insects and Animal Matter
While plants form the majority of their diet, chipmunks supplement their intake with animal matter, which provides necessary protein and nutrients. They are opportunistic predators and scavengers, actively hunting for small invertebrates found in the soil and leaf litter.
Their diet includes grubs, earthworms, beetles, and various other insects and arthropods. For a higher protein meal, chipmunks are known to prey on bird eggs and newly hatched nestlings discovered near the ground. Occasionally, they will also consume small amphibians, such as frogs, or scavenge on carrion when available.
Foraging Near Human Habitation
Chipmunks that establish territories near human settlements quickly adapt their foraging habits. Bird feeders are an especially strong attractant, as chipmunks readily consume dropped sunflower seeds, millet, and corn from the ground beneath the feeders.
Gardens and cultivated areas often suffer from chipmunk activity, as they will readily consume soft-fleshed vegetables and fruits, including tomatoes, strawberries, and corn kernels. They also disturb flower beds by digging up and eating bulbs, which they mistake for nutrient-rich storage organs.
The presence of human food waste often leads to a shift in their behavior. They may also access pet food, such as dry dog or cat kibble left outdoors, which offers another dense source of protein and fat.
The Mechanics of Eating and Storing Food
A chipmunk’s feeding strategy relies on its large, elastic cheek pouches. These pouches can stretch significantly, sometimes to nearly the size of the animal’s head, allowing them to carry a remarkable amount of food in a single trip. For instance, a single chipmunk can stuff up to 70 sunflower seeds or over 30 beech nuts into its pouches before returning to its burrow.
This efficient transport system is vital for their winter survival strategy, as chipmunks do not accumulate enough body fat for a full hibernation. Instead, they enter a state of torpor, waking periodically to feed on their stored caches. They are “larder hoarders,” meaning they deposit their collected food into specialized chambers within their underground burrows. This stored food is what sustains them through the cold months until spring.