Chipmunks are classified as four genera:
Tamias, of which the
eastern chipmunk (
T. striatus) is the only living member;
Eutamias, of which the
Siberian chipmunk (
E. sibiricus) is the only living member;
Nototamias, which consists of three extinct species, and
Neotamias, which includes the 23 remaining, mostly western North American, species. These classifications were treated as subgenera due to the chipmunks' morphological similarities. As a result, most taxonomies over the twentieth century have placed the chipmunks into a single genus. Joseph C. Moore reclassified chipmunks to form the subtribe Tamiina within the tribe
Marmotini in a 1959 study, and this classification of three living genera of chipmunks rather than a single chipmunk genus has been supported by studies of
mitochondrial DNA performed from 2000 to 2010. The common name originally may have been spelled "chitmunk", from the native
Odawa (Ottawa) word
jidmoonh, meaning "red squirrel" (
cf. Ojibwe ajidamoo). The earliest form cited in the
Oxford English Dictionary is "chipmonk", from 1842. Other early forms include "chipmuck" and "chipminck", and in the 1830s they were also referred to as "chip squirrels", probably in reference to the sound they make. In the mid-19th century,
John James Audubon and his sons included a lithograph of the chipmunk in their
Viviparous Quadrupeds of North America, calling it the "chipping squirrel [or] hackee". Chipmunks have also been referred to as
ground squirrels (although the name "ground squirrel" may refer to other squirrels, such as those of the genus
Spermophilus). ==Diet==