Chipmunks, small and agile rodents, are a common sight in many North American landscapes during warmer months. These busy creatures spend a significant portion of their active season gathering and storing food. As the cold grip of winter approaches, many wonder how these small animals sustain themselves when their usual food sources become scarce or inaccessible.
Winter Habits
Chipmunks do not enter a state of deep, continuous hibernation like some other mammals. Instead, they exhibit a behavior known as torpor or semi-hibernation. During this period, their body temperature, heart rate, and metabolic activity significantly decrease, allowing them to conserve energy. This reduced state of activity enables them to survive periods of extreme cold and limited food availability.
They periodically awaken from this torpor, sometimes every few days or weeks, depending on the ambient temperature and their energy reserves. These awakenings are brief but energy-intensive, requiring a temporary increase in metabolic rate. The purpose of these awakenings is to consume stored food and replenish energy.
Stored Provisions
The main sustenance for chipmunks during winter comes from the extensive food caches they prepare throughout late summer and fall. They gather a wide variety of items, which they transport in their expandable cheek pouches to their underground burrows. Their diet primarily consists of nuts such as acorns, hickory nuts, and beech nuts, along with various seeds from trees and plants like sunflower, maple, and pine.
Beyond nuts and seeds, chipmunks also store dried berries, fungi, and kernels of corn. These provisions are stashed in chambers within their burrow system, near their nesting area. When a chipmunk awakens from torpor, it can easily access these stored provisions without venturing outside. This cached food provides energy for their awakenings and physiological processes.
Opportunistic Foraging
While stored provisions are their primary food source, chipmunks might occasionally engage in opportunistic foraging during mild winter days. If temperatures rise above freezing, a chipmunk might emerge from its burrow. These excursions are rare and short-lived, driven by mild weather and a need for sustenance.
During these rare ventures, a chipmunk might search for remaining seeds not covered by snow, or exposed dormant insects. They might also visit bird feeders to consume fallen seeds. These instances are supplementary and not a reliable food source. Their winter survival depends on careful planning and extensive food storage from prior months.