| Least chipmunk | |
|---|---|
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Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Sciuridae |
| Genus: | Neotamias |
| Species: | N. minimus |
| Binomial name | |
| Neotamias minimus (Bachman, 1839) | |
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| Distribution of the least chipmunk | |
| Synonyms | |
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The least chipmunk (Neotamias minimus) is the smallest species of chipmunk [2] and the most widespread in North America.
It is the smallest species of chipmunk, measuring about 15.7–25 cm (6.2–9.8 in) in total length with a weight of 25–66 g (0.88–2.33 oz). [3] The body is gray to reddish-brown on the sides, and grayish white on the underparts. The back is marked with five dark brown to black stripes separated by four white or cream-colored stripes, all of which run from the nape of the neck to the base of the tail. Two light and two dark stripes mark the face, running from the tip of the nose to the ears. The bushy tail is orange-brown in color, and measures 10–11 cm (3.9–4.3 in) long. [4] In some areas, where range overlap with the yellow-pine chipmunk occurs, it may be difficult or impossible to distinguish the two species in the field; laboratory examination of skeletal structures may be required. [5]
As in other chipmunks, there are four toes on each of the forefeet and five on the hindfeet. Females have eight teats. The brain to body mass ratio for least chipmunks is lower than that for other species of chipmunk living in the same area, suggesting that they prefer less complex environments. [6]
Least chipmunks are found through most of the western United States from northern New Mexico and western North and South Dakota to eastern California, Oregon and Washington, and throughout much of southern and western Canada from Yukon and southeastern British Columbia [7] to central Ontario, and into the Upper Peninsula of Michigan and neighboring parts of Wisconsin and Minnesota. Throughout this range, as many as 21 subspecies have been identified. [4] Less arboreal than other chipmunks, [4] least chipmunks are commonly found in sagebrush habitats and coniferous woodland, and along rivers, but they also occur in alpine meadows, and on the edges of the northern tundra. [1]
Least chipmunks are diurnal and eat seeds, berries, nuts, fruits and insects. They mark areas depleted of suitable food with urine, and do not return to such patches afterwards. [8] Home ranges vary widely, and have been reported to vary from 0.1 ha (0.25 acres) in northern Michigan [4] to as much as 5.5 ha (14 acres) in Colorado. [9] Because of their small size, least chipmunks are generally subordinate to yellow-pine chipmunks, which are able to drive them away from food resources where food is plentiful. However, because they need to eat less food in order to survive, least chipmunks are more numerous where resources are scarce. [10] They are agile animals, and have been recorded running at speeds of up to 7.7 km/h (4.8 mph) in natural conditions. [11]
Predators include hawks, owls, and mustelids.[ citation needed ]
Least chipmunks spend the winter in burrows and also scatter-hoard food in numerous concealed pits beneath logs and similar cover. Burrows consist of a single chamber about 15 cm (5.9 in) across and tunnels 7.5 cm (3.0 in) in diameter, averaging 1.7 m (5 ft 7 in) in length. They have two to four entrances, often concealed by nearby rocks, and are typically about 18 cm (7.1 in) below the surface. [4] During the summer they may construct temporary nests in trees from leaves and grass, [12] or appropriate hollows made by woodpeckers. [4]
Least chipmunks do not hibernate, or put on excess fat in the fall. Instead, they survive the winter by entering torpor for long stretches of time, waking to eat food cached in the burrow. How much of each winter they spend below ground in this manner depends on the latitude, varying from late November to mid March in Michigan to mid October to late April in northern Manitoba. [4]
Females enter estrus within a week of emerging from their burrow in the spring, and mating typically takes place between March and May. Gestation lasts 28 to 30 days, with a single litter of three to seven young being born each year; females who lose their first litter soon after birth may, however, sometimes be able to breed again in the same year. The young are born hairless and blind, measuring about 5 cm (2.0 in) in length, and weighing 6 g (0.21 oz). They are able to stand and open their eyes at 27 days, and are weaned at 36 days. They are sexually mature at one year, but do not always breed until their second year. They can live for up to six years in captivity. [4]
Chipmunks are small, striped rodents of Sciuridae, the squirrel family; specifically, they are ground squirrels (Marmotini). Chipmunks are found in North America, with the exception of the Siberian chipmunk which is found primarily in Asia.
Ground squirrels are rodents of the squirrel family (Sciuridae) that generally live on the ground or in burrows, rather than in trees like the tree squirrels. The term is most often used for the medium-sized ground squirrels, as the larger ones are more commonly known as marmots or prairie dogs, while the smaller and less bushy-tailed ground squirrels tend to be known as chipmunks.
The desert woodrat is a species of pack rat native to desert regions of western North America.
The Siberian chipmunk, also called common chipmunk, is native to northern Asia from central Russia to China, Korea, and Hokkaidō in northern Japan. It was imported from South Korea and introduced in Europe as a pet in the 1960s.
The alpine chipmunk is a species of chipmunk native to the high elevations of the Sierra Nevada of California.
The yellow-pine chipmunk is a species of order Rodentia in the family Sciuridae. It is found in parts of Canada and the United States.
The gray-footed chipmunk is a terrestrial and forest-dwelling species of chipmunk and rodent in the family Sciuridae. It is endemic to New Mexico and in the Sierra Diablo and Guadalupe Mountains in the Trans-Pecos region of Texas in the United States. Its natural habitat are coniferous forests. First discovered in 1902, they are distinguished by the unique gray dorsal colouring on the hind feet, hence the common name. They demonstrate sexual dimorphism, and the female is larger than the male.
The gray-collared chipmunk is a species of rodent in the family Sciuridae. It is endemic to Arizona and New Mexico in the United States.
Merriam's chipmunk is a species of rodent in the family Sciuridae. It is found in central and southern California in the United States and a small area in northern Baja California, Mexico.
The yellow-cheeked chipmunk, also known as the redwood chipmunk, is a species of rodent in the squirrel family, Sciuridae. It is endemic to areas near the coast of northern California in the United States where it inhabits coastal coniferous forest.
Palmer's chipmunk is a species of rodent in the family Sciuridae, endemic to Nevada. Its natural habitat is temperate forests. It is threatened by habitat loss. It is named after Theodore Sherman Palmer, an American botanist and zoologist.
The Colorado chipmunk is a species of chipmunk in the squirrel family Sciuridae. It is endemic to Colorado, Utah, Arizona and New Mexico in the United States.
The red-tailed chipmunk is a species of rodent in the family Sciuridae. It is found in Alberta and British Columbia in Canada and Montana, Idaho and Washington in the United States.
Allen's chipmunk, also known as the shadow chipmunk, is a species of chipmunk native to the western United States. Occurring in California, Oregon, and Nevada, it is a common species of the Sierra Nevada.
The Siskiyou chipmunk is a species of rodent in the family Sciuridae. It is endemic to northern California and central Oregon in the United States.
The Sonoma chipmunk is a species of rodent in the squirrel family Sciuridae. It is endemic to northwestern California in the United States. Members of Neotamias are characterized by having two premolars. N. sonomae has two subspecies: N. s. alleni and N. s. sonomae.
The Lodgepole chipmunk is a species of rodent in the family Sciuridae. It is found in the U.S. state of California at elevations from 1,500 to 3,000 metres. The Lodgepole chipmunk has a variety of common names including: Tahoe chipmunk, Sequoia chipmunk, Mt. Pinos chipmunk, and San Bernardino chipmunk.
The Uinta chipmunk or hidden forest chipmunk, is a species of chipmunk in the family Sciuridae. It is endemic to the United States. Formerly known as Tamias umbrinus, phylogenetic studies have shown it to be sufficiently distinct from the eastern chipmunk as to be placed in a separate genus, Neotamias. The same studies have also suggested that Palmer's chipmunk may actually be a subspecies of Uinta chipmunk, although the two are still generally regarded as separate species.
Neotamias is a genus of chipmunks within the tribe Marmotini of the squirrel family. It contains 23 species, which mostly occur in western North America. Along with Eutamias, this genus is often considered a subgenus of Tamias.
The Ezo chipmunk is a subspecies or local population of the Siberian chipmunk; it is found in what was once known as Ezo, namely Hokkaidō, Japan, and Sakhalin and the Southern Kuriles, Russia.
