Chipmunk is the common name for any small squirrel-like rodent species of the genus Tamias.

Etymology and taxonomy

Tamias is Greek for "storer," a reference to the animals' habit of collecting and storing food for winter use. The genus includes twenty-five recognized species, with one species in northeastern Asia, one in eastern North America, and the rest native to western North America.

Some authors have recently suggested that Tamias be subdivided into three genera, corresponding to currently recognized subgenera Tamias, Eutamias, and Neotamias. This usage, however, has not been widely adopted.

The common name originally may have been spelled "chitmunk" (from the Odawa word jidmoonh, meaning "red squirrel"; (c.f. Ojibwe, ajidamoo). However, the earliest form cited in the Oxford English Dictionary (from 1842) is "chipmonk". Other early forms include "chipmuck" and "chipminck", and in the 1830s they were also referred to as "chip squirrels," possibly in reference to the sound they make. They are also called "striped squirrels", "chippers", "munks", "timber tigers", or "ground squirrels", though the name "ground squirrel" usually refers to members of the genus Spermophilus. Tamias and Spermophilus are only two of the 13 genera of ground-living sciurids.

Ecology and life history

Eastern chipmunks mate in early spring and again in early summer, producing litters of four or five young twice each year. Western chipmunks only breed once a year. The young emerge from the burrow after about six weeks and strike out on their own within the next two weeks. Chipmunks have an omnivorous diet consisting of grain, nuts, birds' eggs, small frogs, fungi, worms, and insects. At the beginning of autumn, many species of chipmunk begin to stockpile these goods in their burrows, for winter. Other species make multiple small caches of food. These two kinds of behavior are called larder hoarding and scatter hoarding. Larder hoarders usually live in their nests until spring.

Chipmunks play an important role as prey for various predatory mammals and birds, but are also opportunistic predators themselves, particularly with regard to bird eggs and nestlings. In Oregon, Mountain Bluebirds (Siala currucoides) have been observed energetically mobbing chipmunks that they see near their nest trees.

Chipmunks construct expansive burrows which can be more than 3.5 m in length with several well-concealed entrances. The sleeping quarters are kept extremely clean as shells and feces are stored in refuse tunnels.

Species

• Alpine Chipmunk, Tamias alpinus
• Yellow-pine Chipmunk, Tamias amoenus
• Buller's Chipmunk Tamias bulleri
• Gray-footed Chipmunk, Tamias canipes
• Gray-collared Chipmunk, Tamias cinereicollis
• Cliff Chipmunk, Tamias dorsalis
• Durango Chipmunk, Tamias durangae
• Merriam's Chipmunk, Tamias merriami
• Least Chipmunk, Tamias minimus
• California Chipmunk, Tamias obscurus
• Yellow-cheeked Chipmunk, Tamias ochrogenys
• Palmer's Chipmunk, Tamias palmeri
• Panamint Chipmunk, Tamias panamintinus