Taxonomy and systematics Edit
Chipmunks may be classified either as a single genus, Tamias, or as three genera: Tamias, which includes the eastern chipmunk; Eutamias, which includes the Siberian chipmunk; and Neotamias, which includes the 23 remaining, mostly western, species. These classifications are arbitrary, and most taxonomies over the twentieth century have placed the chipmunks in a single genus. However, studies of mitochondrial DNA show that the divergence between each of the three chipmunk groups is comparable to the genetic dissimilarity between Marmota and Spermophilus. The genus name Tamias is Greek for "treasurer", "steward", or "housekeeper", which is a reference to the animals' role in plant dispersal through their habit of collecting and storing food for winter use.
Chipmunks have an omnivorous diet primarily consisting of seeds, nuts and other fruits, and buds. They also commonly eat grass, shoots, and many other forms of plant matter, as well as fungi, insects and other arthropods, small frogs, worms, and bird eggs. Around humans, chipmunks can eat cultivated grains and vegetables, and other plants from farms and gardens, so they are sometimes considered pests. Chipmunks mostly forage on the ground, but they climb trees to obtain nuts such as hazelnuts and acorns. At the beginning of autumn, many species of chipmunk begin to stockpile nonperishable foods for winter. They mostly cache their foods in a larder in their burrows and remain in their nests until spring, unlike some other species which make many small caches of food. Cheek pouches allow chipmunks to carry food items to their burrows for either storage or consumption.