Like most of the squirrel tribe, they are endowed with much curiosity, and at the appearance of anything unusual, but not too alarming, they seek some safe vantage point from which to peer at it with every sign of interest. They are extremely timid and wary, however, and if doubtful move by little cautious runs, stopping to sit up and look about, often mounting a stump, log, or a side of a tree trunk for the purpose, the tail all the time moving with slow undulations. If alarmed they dash away to the nearest shelter, the tail held nearly or quite erect and sometimes quivering excitedly. When running to shelter they often utter chattering cries of alarm. Their principal enemies are cats, weasels, martens, foxes, snakes, birds of prey, and the untamed small boy with his dog. Weasels, the supreme terror of their existence, follow them to the depths of their burrows and kill them ruthlessly.
These chipmunks are sociable and playful, often pursuing one another, first one and then the other being the pursuer, as though in a game. They race along fence tops and old logs and up stumps and even the lower parts of tree trunks. Lovers of bright, sunny weather, they usually remain hidden in their burrows during stormy days. If they venture out at such times they are quiet and show none of the mercurial liveliness which characterizes them when the weather is pleasant.
Their food includes a great variety of cultivated and wild plants, as wheat, buckwheat, corn, grass seed, ragweed seed, hazelnuts, acorns, beechnuts, strawberries, blueberries, wintergreen berries, mushrooms, and many others. In addition they eat May beetles and other insects and insect larvæ, snails, occasional frogs, salamanders, small snakes, and many young birds and eggs.
At all seasons they fill their cheek pouches with food to be carried away to their dens, but toward the end of summer or early fall they work industriously laying up stores of seeds and nuts. Sometimes these stores, hidden in chambers excavated for the purpose or in hollow logs and similar places, contain several quarts of beechnuts or other nuts or seeds. Small quantities of such food are hidden here and there under the leaves or in shallow pits in the ground. Store-rooms in one burrow contained a peck of chestnuts, cherry pits, and dogwood berries, and another had a half bushel of hickory nuts.
ABERT SQUIRREL
Sciurus aberti KAIBAB SQUIRREL
Sciurus kaibabensis
While at a summer camp I once saw one of these chipmunks give an exhibition of the exquisitely keen power of scent which must be necessary to recover scattered stores. The chipmunk had been coming repeatedly down a wooded slope in full view for twenty-five yards or more to the floor of the porch for food supplied by the campers. While it was absent carrying food to its burrow I placed a few nut meats on the flat top of a stump about fifteen feet to one side of the porch and farther away than the point where the chipmunk was being fed bread crumbs. On its return several minutes later, instead of going as usual to the porch, it ran directly to the stump, climbed up it, and promptly made off with the nuts, which it had evidently located from afar. They sometimes climb beeches and other trees to gather nuts even to a height of fifty or sixty feet, and are commonly seen on low limbs and in bushes.
FLYING SQUIRREL
Glaucomys volans