Field Guide/Mammals/Least Chipmunk

Tamias Minimus (Least Chipmunk)

Family: Sciuridae Size: Range mass: 1.48oz-1.87oz (42g-53g) Range length: 7.28in-8.74in (185mm-222mm) Range length of tail: 81mm-95mm Description: The least chipmunk is the smallest of all the chipmunks. In some of the chipmunk population the female are bigger than the male. They have three dark and two light stripes on the face, with five dark and four light stripes along the sides which the middle strip runs all the way to the tail. Their fur colors are orangish-brown and grayish-white. The tail is long and bushy with a pale brown color to it. Habitat: They live throughout North America from the Rocky Mountain regions to the western Great Plains. They are also found throughout central and western Canada, and in the states of Wisconsin, Minnesota, and Michigan. They prefer more open areas like forest edges and the openings. Some common places are near rock cliffs, river bluffs and open pine stands. The least chipmunk is the most widespread North American chipmunk, both in their geographic range and habitats (Harris, 1999). Diet: The least chipmunks eat a variety of food which their diet consist of seeds, nuts, berries, fruits, grasses, fungi, snails, insects and possibly some small birds or mammals (Schlimme, 2000). These chipmunks spend most of their time from April through October foraging. Their cheek pouches allow them to carry food items back to their nests and are either eaten or store. They feed on ground, in shrubs or up in the trees and store food underground to use during winter (Harris, 1999). Activity: When it’s cold the least chipmunks will climb on trees to keep themselves warm in the sun. They are adept climbers and some of them will make nest high above grounds where their nest are built seasonally. These least chipmunks are most active between the month of April and October. For the summer, their nest will be made from leaves and bark that are in rotting logs and tree cavities. As the winter, their nest will be underground burrows which consist of dried grass, bark, fur, feathers and soft vegetation. Hibernation for the least chipmunks is not as deep as compare to ground squirrels (Schlimme, 2000). Hibernation occurs from October to April and the male enter hibernation first (Harris, 1999). During these winter months and season they often awake to snack on stored food. They are not social except during mating season and during the time they are rearing young. But, when provisioned by humans then they are remarkably tolerant of conspecifics (Schlimme, 2000). Reproduction: The males come out from hibernation before the females do and starts to get involve in competition for mates. Individual are sexually mature by 10 months. The mating season starts in April when females begin to come out of hibernation. Gestation usually last about 28-30 days for the least chipmunks (Harris, 1999). Litter size varies between 2 to 6 young and during a breeding season normally there is only a single litter of off springs but are capable of a second litter if the first one is lost. Young are born from April through May and will appear above ground around June to early July (Harris, 1999). Newborns are naked with a pink color, are 50 mm in length and average about 2.25 g. After the 28th days, their eyes will open and fur will not be fully grown until by the 40th day. Some may move the newborn to tree nest after they begin to activity out of the nest (Harris, 1999). As for lactation it’ll last about 60 days and the newborns will be with their mother for up to six weeks or more. The female will choose their nests for nursery while still pregnant. They are often lines with grass and usually located in stumps, under logs, in brush piles, or even rock piles. The location or position of the chosen nest for nursery will be protected from rainfall and runoff for the health and comfort of the newborns after birth. The role of males in the care for off springs is not certain but some indications are that males may help defend the home range of female with off springs, help maintain the nursery nest, and also bring food. (Schlimme, 2000). Lifespan: The lifespan of these animals has not been reported but are known to be shorter than the Eastern chipmunks, which can live up to 11 years (Schlimme, 2000).