Popular Science Monthly/Volume 7/August 1875/The American Chipmunk
|THE AMERICAN CHIPMUNK.|
By CHARLES C. ABBOTT, M. D.
WITH the first sweet blossoms of the Epigæa, and long before the foremost warbler greets his old-time home with gleesome songs, our little chipmunk has roused himself from his long winter's nap, and, sniffing the south wind, as it whirls the dead leaves about, scampers to and fro while the sun shines, and dives into his winter-quarters, it may be for a whole week, if the north wind whispers to the tall beech-trees. But the blustering days of March give way in due time to showery April, and then, with more courage, "chip" faces the music of the winds, blow they from whatever quarter, and darting along the top rail of our zigzag fences, chatters, scolds, and calls at and to his equally noisy companions. They know full well that they have the summer before them, and, while determined to enjoy it, begin early and in good earnest to make arrangements for its coming duties. We watched several pairs of them from March to November, during the last year (1874), and our sketch is based on numerous notes made at different times.
Until the weather became fairly settled, and really spring-like in temperature, these little chipmunks did not frequently show them-selves, and then only in the middle of the day. The occurrence of a cold storm they appeared to foretell by twenty-four hours, and resumed their hibernating sleep, becoming lethargic, and very difficult to restore to consciousness. A pair that we dug out in March, having two days before reentered their winter-quarters and become again torpid, were apparently lifeless when first taken up in the hands, and not until after several hours' warming did they become lively and altogether themselves again. This seemed to us the more curious, in that they can respond to a favorable change in the weather in a short time, even when the thermometric change is really but a few degrees.
On the 3d of May a pair made their appearance in the yard of our residence, and took up their abode in a stone-wall having a southern outlook, and on the edge of a steep descent of seventy feet; which hill-side is thickly wooded, and harbors scores of these little chipmunks, or "ground-squirrels," as they are more commonly called. From the fact of these little animals living wholly underground, and it being stated that their underground homes were quite elaborate in structure, we determined to wait until the pair in our yard had completed their excavations in and under the stone-wall, and arranged
Fig. 1.—American "Chipmunk" (Tamias Lysteri),half Natural Size.
their nest, which time we judged by their actions, and then seeking out the home of another couple, which was readily accessible, we undertook to expose the nest and its approaches. This we did on May 29th. The general character of the nest and its approaches are seen in the sketch. The nest contained five young, not more than forty-eight hours old. The two entrances were at the foot of a large beech-tree standing about six feet from the brow of the hill. The grass alone grew about the tree, and the holes on the surface of the ground were very conspicuous. No attempt at concealment had been made; but this was evidently because there is here almost a total absence of their particular enemies. Animals soon learn this fact, and their homes and habits vary with the knowledge. From the right-hand entrance to the nest was an intervening space of nine feet traversed by a cylindrical passage somewhat serpentine in its course, which made the distance really about twelve feet. The nest itself was oval, about twenty inches in length (the cut makes it appear too large), and ten inches in height. It was lined with very fine grass. We had hoped to find several passages leading from the nest, and two or more "extra" nests, or magazines for storing away food, but no trace of them was to be found.
On the 23d of June, six young chipmunks made their appearance about the stone-wall in the yard, and to these, with their parents, we will now confine our attention. It puzzles us now when we think of it, to imagine when this company of eight chipmunks took any rest. Very frequently during the summer we were astir at sunrise, but the chipmunks were already on the go, and throughout July they appeared to do little but play; which sporting, by-the-way, is very animated. They seem to be playing at what children know as "tag," i. e., they chase each other to and fro, and try not simply to touch, we should judge, but to bite each other's tail. The way in which they scamper along the tapering points of a paling fence is simply astonishing; but however mad may be their galloping, let a hawk come near, and in a moment every one is motionless. If on a fence, they simply squat wherever they may be at the time, and trust to remaining unnoticed. If on the ground, and not too far from their burrows, which is not often the case, they will dart to their nests with an incredible celerity, going, we believe, the whole length of their passage-way to the nest, turning about, and retracing their steps to the entrance, from which they will peer out, and, when the danger is over, reappear and recommence their sports. These little animals
Fig. 2.—Nest of "American Chipmunk."
play merely for play's sake, and have no more important object in view than amusement. Indeed, so far as we have studied animal life, this indulgence in play, just as children play, and for the same reasons, is common to all animals. We have often seen most animated movements on the part of fishes that could be referred only to play.
That some work was accomplished during July by our eight chipmunks, we have no doubt, as early in August we dug out a nest beneath an oak, on the hill side, and we found, besides the nest proper, two nest-like cavities, and in one of which—that most distant from the nest—was about a quart of yellow corn (maize). We judge, therefore, that these "magazines" were dug out by the chipmunks late in the summer, and similar ones, no doubt, were excavated by the chipmunks in the stone-wall. What they did with the dirt we cannot guess. Certainly not a particle of it could be found about their nests' entrances.
About August 15th they commenced to work in real earnest. Instead of playful, careless creatures, that lived from hand to mouth, they became very sober and busy indeed. Instead of keeping comparatively near home, they wandered to quite a distance, for them, and, filling both cheek-pouches full of corn, chincapins (dwarf chestnuts), and small acorns, home they would hurry, looking, in the face, like children with the mumps. This storing away of food was continued until the first heavy white frosts, when the chipmunks, as a member of Congress once said, went "into a state of retiracy."
The food gathered, we believe, is consumed in part, on their going into winter-quarters, they spending some time in their retreats before commencing their hibernating sleep. This belief, on our part, is based on the result of digging out a third nest on the 3d of November. The last time we noted down seeing a chipmunk belonging to a certain nest was October 22d. Twelve days after we very carefully closed the three passages that led to the nest, and dug down. We found four chipmunks very cozily fixed for winter, in a roomy nest, and all of them thoroughly wide awake. Their store of provisions was wholly chestnuts and acorns, and the shells of these nuts were all pushed into one of the passages, so that there should be no litter mingled with the soft hay that lined the nest. How long this underground life lasts, before hibernation really commences, it is difficult to determine; but as this torpid state does not continue until their food-supply is again obtainable out-of-doors, the chipmunks, no doubt, store away sufficient for their needs throughout the early spring, and perhaps until berries are ripe.
So much for the present year, now nearly passed away; but we are not done with the chipmunks yet, and next year, if all goes well, we purpose to follow the wanderings of the young brood of the past summer, for, we suppose, the old couple will not want them after spring once fairly comes again this way.—Science-Gossip.