Chipmunk

Chipmunks are small, striped squirrels belonging to the subtribe Tamiina. Most chipmunk species live in North America, but the Siberian chipmunk lives primarily in Asia.

These mammals are omnivorous, meaning they eat both plants and animals. Their diet consists mostly of seeds, nuts, fruits, and buds. However, they also consume insects, worms, small frogs, and fungi. Some species even eat bird eggs and nestlings. Because they eat grains and vegetables from farms, humans sometimes view them as pests.

To manage their food, chipmunks use specialized cheek pouches. These pouches allow them to carry many items at once. They transport these items back to their underground homes, known as burrows. Many species begin stockpiling nonperishable foods at the start of autumn. They store these items in a larder inside their burrows. This behavior is different from some other animals that make many small caches. Instead, they rely on these large central stores to survive the winter.

Chipmunk burrows are quite complex and extensive. A burrow can be more than a meter in length. These tunnels include several well-concealed entrances to protect the animals. The structures contain separate compartments for nesting and multiple food chambers. They also feature side pockets and escape routes for safety. Chipmunks keep their sleeping quarters clear of shells. They even use specific refuse tunnels to store feces.

Scientists classify chipmunks into four distinct genera. The genus Tamias includes only one living member, the eastern chipmunk. The genus Eutamias contains only the Siberian chipmunk. The genus Neotamias includes 23 species, mostly in western North America. This group includes the Allen's chipmunk and the Alpine chipmunk. A fourth genus, Nototamias, consists of three extinct species. For much of the twentieth century, scientists grouped them into a single genus. However, Joseph C. Moore reclassified them into the subtribe Tamiina in 1959. Studies of mitochondrial DNA from 2000 to 2010 have supported this classification.

The history of the name "chipmunk" is also quite interesting. It may come from the Odawa word jidmoonh, which means "red squirrel." The earliest English spelling in the Oxford English Dictionary is "chipmonk" from 1842. In the 1830s, they were called "chip squirrels." This name likely refers to the sounds the animals make. In the mid-19th century, John James Audubon included them in his work. He called them "chipping squirrels" or "hackee."

Chipmunks play a vital role in forest ecosystems. Their habit of harvesting and hoarding seeds helps with seedling establishment. When they move seeds in the soil, it leads to plant germination. They also help disperse fungi. They can act as a vector for spores of subterranean sporocarps, such as truffles. This happens as they consume various types of fungi.

There are also differences in how chipmunks live and breed. The eastern chipmunk is the largest species. It mates in early spring and again in early summer. This allows them to produce two litters of four or five young each year. Eastern chipmunks also hibernate during the winter. In contrast, western chipmunks breed only once a year. They do not hibernate but instead eat their stored food. Most chipmunks live about three years in the wild. However, some have lived to nine years in captivity.