जीवाश्म काल: Early Miocene to Recent
Chipmunk is the common name for any small squirrel-like rodent species of the genus Tamias in the family Sciuridae. Around 25 species fall under this name, mainly in North America, although one species is native to Eurasia.
Etymology and taxonomy[संपादित करें]
Tamias is Latin for "storer," a reference to the animals' habit of collecting and storing food for winter use. Twenty-five species belong to the genus by this name, with one species in northeastern Asia, one in eastern North America, and the rest native to western North America.
The 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" or "ground squirrels", though the name "ground squirrel" more often refers to the genus Spermophilus. Tamias and Spermophilus are only two of the 13 genera of ground-living sciurids.
Ecology and life history[संपादित करें]
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.
Though they are commonly depicted with their paws up to the mouth, eating peanuts, or more famously their cheeks bulging out on either side, chipmunks eat a variety of foods. Their omnivorous diet consists 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.
These small squirrels 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.
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.
If unmolested they often become bold enough to take food from the hands of humans. The temptation to pick up or pet any wild animal should be strictly avoided, however. Chipmunk bites can transmit virulent and dangerous bacterial infections. Chipmunks also may attract birds and other predators.
- John O. Whitaker, Jr.; Robert Elman (1980). The Audubon Society Field Guide to North American Mammals (2nd edition ed.). New York: Knopf. pp. 370. आई॰ऍस॰बी॰ऍन॰ 0-394-50762-2.
- Wilson, D. E.; D. M. Reeder (2005). "Mammal Species of the World (MSW)". http://nmnhgoph.si.edu/msw/. अभिगमन तिथि: 2007-06-27.