Written in 2015
If you have a bird feeding station in your backyard, most likely you’ve come across the Eastern Chipmunk, a furry, striped, swift little rodent, trying to forage some seeds and nuts. The Eastern Chipmunk is quite common in Ontario and easy to spot during the spring and summer months. Part of the squirrel family, chipmunks enjoy living in forested areas with low growing plants for protection from predators. As omnivorous rodents, their primary diet consists of nuts, berries, seeds, fruit, grain, insects, and on occasion fungi and slugs. They’ve even been known to eat small birds and snakes!
But what you may not have known is that these cute, little, furry creatures are actually architectural geniuses!
Chipmunks sleep and spend the winter months in elaborate underground burrows, made by digging and carrying away the dirt in their pouched mouths. These burrows can be as much as 30 feet long and 3 feet deep, with multiple rooms and entrances. The entrances are usually concealed with leaves and rocks to keep them hidden from predators, and the burrows are usually built on sloped land to allow water drainage. A typical burrow will consist of two levels – a shallow tunnel closer to ground level, and a deeper tunnel with additional sleeping rooms and storage space. The tunnels are designed with several sleeping areas lined with soft leaves and several food storage areas which are normally located closer to ground level to keep food cool and fresh. Sleeping areas in the level closer to ground are used during the day and during the summer months, allowing the chipmunks to easily go in and out of their burrows. The deeper burrow is used during the winter months.
Chipmunks start preparing for the winter in July by eating extra seeds and nuts to pack on additional fat. During the next few months, as the days become shorter, the chipmunks start carrying seeds and nuts to their burrows, and storing them in designated storage rooms. The amount of food a chipmunk can hold in their cheeks increases with age.
Chipmunks do not hibernate in the winter. Instead, they enter a torpid state called superficial or shallow hibernation. The chipmunk withdraws to its burrow in the late fall and enters a deep sleep during which its body temperature is somewhat reduced and its metabolism slowed. Unlike real hibernation, superficial hibernation allows the chipmunk to awaken approximately every two weeks to eat food from its storage rooms. It does this in a half-asleep state, almost as if it’s sleep walking! Most chipmunks emerge from their hibernation in early March, however they are also known to come out during the winter months in search of more food on days where the weather is unusually warm with less snow cover.