Fussy, fleet, and frisky, the nervous, bright-eyed little chipmunk is the dynamo of the rodent clan. He is curious about everything that is occurring in his environment, yet he is extremely wary. He has to be as his only defenses against numerous predators are his alertness, intelligence, and speed.
During the warm months of the year, the chipmunk is a familiar sight in northern Illinois, and the broad stripes along the back easily distinguish him from any other mammal in the state.
There are several species of chipmunks in the United States, but the eastern chipmunk is the one we have in this area. Its scientific name is Tamias stratus, which describes this small ground squirrel perfectly. Tamias means a steward, one who stores and looks after provisions, and striatus means striped.
Though the chipping squirrel, as it is sometimes called, is on constant alert for predators, it can become quite friendly when it perceives there is no danger. Last summer, I finally convinced one I had affectionately named Alvin to eat out of my hand.
Alvin was a daily visitor to my bird feeder I have erected in the back yard, and one day when I had forgotten to replenish the supply of seeds in the feeder, the rodent came to the glass door to the porch and looked inward, as if begging for breakfast. I sat on the porch and extended a hand containing seed, and he gazed longingly at the tempting meal. He did not, however, have enough courage to come and get it. I did this for several days, until finally little Alvin threw all caution to the wind and actually ate out of my hand.
This small ground squirrel spends a good portion of the year underground, living in an extensive system of burrows it has excavated. These burrows are often intricate, with many side passages that may extend for 30 feet or so. Special cells are created for different purposes. Some are food storage areas, while others are designed to hold waste products, including fecal material and shells of nuts and seeds. One cell is used as the master bedroom and contains a warm, comfortable nest where the rodent may sleep in comfort.
Chipmunks do not go into true hibernation as many animals in the northland do. As winter approaches, they dont stuff themselves with rich food to establish a layer of fat to be metabolized during the long winter sleep. Rather, the chipmunk stores large amounts of seed and other non-perishable items in storage cells within the burrow. Pangs of hunger may awaken it from a prolonged snooze, and the chipmunk simply visits its larder, fills it stomach, and goes back to sleep.
The chipmunk has no internal clock that dictates how long it must sleep, and if it awakens and perceives that the weather is warm outside, it may venture from the burrow to evaluate the situation. It is, therefore, not unusual to see a chipmunk scampering around your backyard in February or early March if the temperature is unusually warm.
The chipmunk has an unusual adaptation that makes the transportation of food both simple and amazing. It has two large internal cheek pouches into which food is meticulously stuffed and thus carried from place to place. It uses its forepaws to maneuver the food into the pouches, and it is always careful to balance the load properly. When it unloads the pouches it uses the forepaws externally, shoving and pushing upwards so that the food can be taken into the mouth and then deposited into the cache. A chipmunk with loaded pouches always appears to me to be suffering from a severe case of mumps.
Economically, the chipmunks rarely interfere with mans interests, and people seem to enjoy their presence, so a workable live and let live policy is generally the order of the day. They may invade basements and garages on occasion and cause some damage to storage products In that case, they are easily snared in live traps and taken to another area for release.
It appears that a single individual spends the greater portion of its life within an area not greater than one acre, and for the most part, confines its home range to a circle about 100 feet in diameter. So, that chipmunk you see roaming around in your backyard is one that has bestowed upon you the respect of selecting your premises to set up housekeeping. In a way, you should feel honored. Offer him and his family your hospitality and you will be rewarded by hours of amusement and free education in natural history.
Dr. Robert Hedeen is a former resident of Marylands eastern shore and resided in the Chicago area from 1960-1971. He is a retired professor emeritus of biological sciences in the University of Maryland system. He has published more than 30 scientific papers, has written numerous magazine articles, and is the author of two books on the natural history of the Chesapeake Bay.