Friday, October 13, 2006
Eastern chipmunk — Tamias striatus
Our beloved (or not, depending on your yard and plants) chipmunk is of the order Rodentia, that is, first of all, a rodent — and secondly of the family Sciuridae, the squirrels, another of our forest friends.
Chipmunks are very common in New England and range from Quebec south through the eastern half of the U.S. into Georgia, western Florida, and northeastern Louisiana. Other species of chipmunks are found out west in eastern Oklahoma, Kansas, the Dakotas and Saskatchewan.
The "chippy" likes living in the borders of open deciduous woods or scampering among rocky places with brush and vines, stone walls or even in old forests without underbrush. Rubbish heaps can be an attraction harboring a tasty snack. Its home is an underground den with a simple or extensive burrow system up to ten feet long and less than three feet deep. It includes enlarged cavities for nests and storage of food which can last until the following spring and summer. The entrance is largely hidden under a rotting log, stone wall, rock, or old tree stump and it is plugged up against the cold in winter. Usually solitary animals, when chipmunks are feeding, larger dominates smaller, and they chase each other on merry dashes all around the bushes, rocks and forest — a laughable sight.
The eastern chipmunk is an active, yet graceful beautifully colored squirrel, only one third the size of the gray squirrel. Its fur is short, dense and soft. Males and females have similar coloring — a reddish brown above with a mixture of black and white hairs that blend into a rusty color on the flanks and rump. There is a black stripe across the eyes and a whitish stripe above and below. A dark brown stripe between two white stripes runs from the shoulders to the rump and there is another larger black stripe down the center of the back. The species name, striatus, means striped. (On my earlier travels, I took a photo of the western chipmunk which has much wider side stripes.) The tail is small, compact, and not bushy. The feet are buff-colored and the belly is white. Coloration is paler in the winter. Albino and black chipmunks are possible.
These pert creatures, although generally ground dwellers, can climb oak trees when acorns are ripe. They also like hickory nuts and hazel nuts. If you hear any loud cutting sounds in an otherwise silent forest, chances are that it's a chippy eating nuts. It is amusing to watch them feed. They are compulsive hoarders of food.
The genus name Tamias, meaning steward, refers to the gathering and tending of food stores chippies are constantly gathering, seeds and nuts which they stuff into their expandable cheek pouches. They can fit in as many as 31 corn kernels and up to 70 sunflower seeds. The food is taken back to the burrow or buried in some secret place for later meals. One documented case of a single-minded chipmunk gathering food found that, in three days, it had stored a bushel of chestnuts, hickory nuts, and corn kernels — a marathon of making trips from tree to storage burrow almost continuously. Chippies also eat seeds and other vegetation as well as slugs, snails and some small carrion.
Chipmunks lightly hibernate in the winter. They retire to their burrows in late October and wake about every two weeks to feed. They emerge in late February or early March to breed. If the winter has been harsh, some may become inactive again until spring. Breeding can also occur in summer. Chippies have three to five babies which are born 31 days after mating. The red, naked and blind babies open their eyes in about a month and shed milk teeth in three months. The average lifespan of wild chipmunks is only two to three years. Predators include weasels, hawks, foxes, raccoons, red squirrels, large snakes, bobcats and house cats.
Sources: Wild Mammals of New England by Alfred J. Godin; National Audubon Society Field Guide to North American Mammals by John O. Whitaker; and my own personal observations.
Topics for the Biodiversity Corner do not have to be rare or uncommon species. If you have a favorite, like the chippy, write it up and send it to email@example.com. It should be something that exists in the wild and was seen in Carlisle.
© 2006 The Carlisle Mosquito