chipmunk

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Chipmunks Fossil range: Early Miocene to Recent
Tamias minimus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Suborder:	Sciuromorpha
Family:	Sciuridae
Tribe:	Marmotini
Genus:	Tamias Illiger, 1811
Species
25 species

Chipmunks are small squirrel-like rodents of the genus Tamias. They are native to North America and Asia.

Etymology and taxonomy

Tamias is Greek for "storer," a reference to the animals' habit of collecting and storing food for winter use.^[1] The genus includes twenty-five recognized species,^[2] 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 should be subdivided into three genera, corresponding to currently recognized subgenera Tamias, Eutamias, and Neotamias.^[3] 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.^[4] 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.^[5] Chipmunks have an omnivorous diet consisting of grain, nuts, birds' eggs, small frogs, fungi, worms, and insects.^[4] 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.

These small mammals fulfill several important functions in forest ecosystems. Their activities harvesting and hoarding tree seeds play a crucial role in seedling establishment. They consume many different kinds of fungi, including those involved in symbiotic mycorrhizal associations with trees, and are an important vector for dispersal of the spores of subterranean sporocarps (truffles) which have co-evolved with these and other mycophagous mammals and thus lost the ability to disperse their spores through the air.^[6]

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.^{[citation needed]}

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.

Chipmunk with a human hand for size comparison

Chipmunk inside Zion National Park

Chipmunk in the Capitol Reef National Park, USA (39 sec.)

Chipmunks sold as pets at a bazaar in Linxia City, China

Species

Notes

References

• Nichols, John D. and Earl Nyholm (1995). A Concise Dictionary of Minnesota Ojibwe. Minneapolis: University of Minnesota Press.

External links

• Media related to Tamias at Wikimedia Commons
• Etymology Online: Chipmunk
• Wildlife and Nature - Chipmunk
• Chipmunk Photographs showing food-carrying habit

Further Reading

• Baack, Jessica K. and Paul V. Switzer. "Alarm Calls Affect Foraging Behavior in Eastern Chipmunks (Tamias Striatus, Rodentia: Sciuridae)." Ethology. Vol. 106. Dec. 2003. 1057-1066.
• Gordon, Kenneth Llewellyn. The Natural History and Behavior of the Western Chipmunk and the Mantled Ground Squirrel. Oregon: 1943