March 11, 2010

Chipmunk Revelations

Chipmunk Revelations

By Margaret Gillespie, Illustration by Cheryl Johnson

How many chipmunks are there in New Hampshire? This student question may first bring a chuckle as we contemplate an answer of “many” or perhaps, “too many!” Underlying this innocent question is a sense of curiosity that we don’t want to lose in ourselves or in the children in our lives. We see this interest too in visitors from Great Britain and other parts of Europe who come to see New England fall colors and become captivated by chipmunks running freely about the trails at the Science Center. Are we missing something? In this article, I am taking the challenge to uncover facets of chipmunks that may not be common knowledge and could perhaps cause us to turn our heads the next time a chipmunk scampers by.

Take stock of your CSI (Crime Scene Investigation) skills or, more precisely, check your observation skills. Tamias striatus is the scientific name for the eastern chipmunk, meaning “striped storer.” From memory, can you describe the stripes on a chipmunk’s back? Here is the answer – there is a long dark central stripe and then a white stripe on each side flanked by two dark stripes. In one of my favorite Native American stories, a chipmunk is collecting woodland berries on a bush but stays out after dark against his grandmother’s instructions. Along comes an owl walking through the leaves. This owl encourages him to jump down to him and the owl covers his eyes with his wings. Although the owl promises not to look, of course he secretly peers through the feathers. Leaping quickly, the chipmunk manages to escape but takes with him stripes along his back from the owl’s talons!

In the Tamias part of the chipmunk’s scientific name, this rodent of the squirrel family is referred to as a “storer.” Speaking of gathering and storing food, how do those cheek pouches work? It is not only a question of skin stretching to make room for acorns and other nuts. These pouches are actual storage cavities with an opening close to the lips on each side. When it is discharge time, chipmunks use their paws to push against their cheeks and the contents emerge. Chipmunks will transport bedding in their cheek pouches too – I’ve observed chipmunks stuffing in dried leaves to take to their dens for winter comfort or for their young’s nest in spring.

When walking through the woods, I listen for animals alert to my presence. Blue jays may be making their “jay” calls or red squirrels chattering a warning. Chipmunks too show their alarm but with a repetitive single note “chuk” sound that is often taken up by neighboring chipmunks until the whole hillside is spreading the news. In another call, chipmunks are said to “sing” with a series of chips uttered rapidly over several minutes – a call which may help define territory. Take time to listen to the chipmunks! See if you can interpret what they are announcing.

Have you ever watched a chipmunk run across the lawn and abruptly disappear? Upon closer observation, you notice a 1.5 to 2-inch hole hidden in the grass with no evidence of any excavated material. How do they engineer that feat? The hole you are observing is actually the end product! The chipmunk started some 30 or 40 feet away by digging a tunnel and a roomy living chamber. With its nose, this rodent plowed the discarded earth above ground where it dispersed the soil in all directions. The chipmunk then continued with the final tunnel, packing the soil in the old tunnel and sealing the original hole. When the chipmunk reached the surface with its new tunnel, there would be no stray soil to betray the entrance to predators! Watch a feeding chipmunk closely and it may show you its den entrance as it descends to store food.

Fall is the chipmunks’ busy season as they gather and stow away acorns, beechnuts, and sunflower and other seeds under the leaves in their sleeping chambers or in storage chambers of their burrows. These striped rodents respond to winter quite unlike groundhogs that hibernate and rely on accumulated fat to sustain them. Chipmunks, on the other hand, alternate between a torpid state and wakefulness. During torpidity, the chipmunks’ body temperature and respiration decrease as they conserve energy. Periodically they wake up to feed on their bounty.

Are you ready for spring to arrive? Chipmunks reward us with some of the earliest signs of warming weather as they emerge and dance along the stone walls, their brown streaked bodies highlighted against the remaining patches of snow. Later, young chipmunks about six weeks old will be cavorting around the den’s entrance. More clumsy, tentative, playful, and inquisitive than adults, these youngsters are about two-thirds grown and this family time is fleeting. In a week or two they will be off to find their own places. Like these young chipmunks, let us take advantage of the fresh sights and sounds of spring. After all, spring comes only once a year!

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