Chipmunks are small, striped rodents of the family Sciuridae.
All species of chipmunks are found in North America, with the exception of the Siberian
chipmunk, which is found primarily in Asia.
Taxonomy and systematics 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.
The common name originally may have been spelled "chitmunk," from the native Odawa word jidmoonh,
meaning "red squirrel".
The earliest form cited in the Oxford English Dictionary is "chipmonk," however, "chipmunk"
appears in several books from the 1820s and 1830s.
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-1800s, 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 "striped squirrels," "chippers," "munks," "timber tigers,"
or "ground squirrels".
Diet
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 multiple small caches of food.
Cheek pouches allow chipmunks to carry multiple food items to their burrows for either storage
or consumption.
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 breed only once a year.
The young emerge from the burrow after about six weeks and strike out on their own within
the next two weeks.
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 which have co-evolved with these and other mycophagous mammals and thus lost
the ability to disperse their spores through the air.
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.
The eastern chipmunk hibernates in the winter, while western chipmunks do not, relying on
the stores in their burrows.
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 have been observed energetically mobbing chipmunks that they
see near their nest trees.
Chipmunks typically live about three years, although have been observed living to nine
years in captivity.
Chipmunks in captivity are said to sleep for an average of about 15 hours a day.
It is thought that mammals which can sleep in hiding, such as rodents and bats, tend
to sleep longer than those that must remain on alert.
Species list Subgenus Eutamias
Siberian chipmunk, Eutamias sibiricus Subgenus Tamias
Eastern chipmunk, Tamias striatus Subgenus Neotamias
Allen's chipmunk, Neotamias senex Alpine chipmunk, Neotamias alpinus
Buller's chipmunk, Neotamias bulleri California chipmunk, Neotamias obscurus
Cliff chipmunk, Neotamias dorsalis Colorado chipmunk, Neotamias quadrivittatus
Durango chipmunk, Neotamias durangae Gray-collared chipmunk, Neotamias cinereicollis
Gray-footed chipmunk, Neotamias canipes Hopi chipmunk, Neotamias rufus
Least chipmunk, Neotamias minimus Lodgepole chipmunk, Neotamias speciosus
Long-eared chipmunk, Neotamias quadrimaculatus Palmer's chipmunk, Neotamias palmeri
Panamint chipmunk, Neotamias panamintinus Merriam's chipmunk, Neotamias merriami
Red-tailed chipmunk, Neotamias ruficaudus Siskiyou chipmunk, Neotamias siskiyou
Sonoma chipmunk, Neotamias sonomae Townsend's chipmunk, Neotamias townsendii
Uinta chipmunk, Neotamias umbrinus Yellow-cheeked chipmunk, Neotamias ochrogenys
Yellow-pine chipmunk, Neotamias amoenus Extinct:
†Tamias aristus See also
Golden-mantled ground squirrel References
Further reading Baack, Jessica K. and Paul V. Switzer.
"Alarm Calls Affect Foraging Behavior in Eastern Chipmunks."
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 External links
Wildlife and Nature – Chipmunk at the Wayback Machine