Two subspecies of Tamias ruficaudus are recognized, T. r. ruficaudus and T. r. simulans. These subspecies are differentiated based on their cranial and bacular morphology. Nevertheless, evidence of interbreeding among these taxa has been discovered, and there appears to be substantial gene flow throughout the species.
The name Tamias comes from the Greek tamias meaning storer or distributor. Ruficaudus is from the Latin rufus meaning reddish, and cauda meaning tail. Other names include rufous-tailed and Coeur d'Alene chipmunk. (Best, 1993; MSW Scientific Names)
Perception Channels: tactile ; chemical
Generally, -Tamias ruficaudus- are abundant in most areas. They seem to have avoided the fate of some of their close relatives, -Tamias palmeri-, -Tamias minimus atristriatus-, and -Tamias quadrivittatus australis-, which have all appeared on the IUCN list or have become extinct. (Nowak, 1999)
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Red-tailed chipmunks typically favor brush-covered or rugged land. However, sometimes they occur near agricultural crops. When this happens, they can do damage by eating planted seed, young forest plantings, and even fruit trees. (Nowak, 1999)
The red-tailed chipmunk can be tamed quite easily for the purposes of laboratory study. (Best, 1993)
Red-tailed chipmunks gather dry food that they carry in their cheek pouches and store underground. They feed at discrete times during daylight hours. These animals become torpid in the winter and feed from time to time upon their larder. Their diet includes the seeds of fir trees, honeysuckles, locusts, and cranberries. In Idaho, they have also been observed feeding upon the seeds of Douglas knotweed. In Montana, the chipmunk eats the fruits and seeds of nine-bark, wild rose, Ponderosa pine, snow brush, serviceberry, big whortleberry, buckbrush, knotweed, grass, huckleberry, mountain maple, and bull thistle. They also eat the leaves and flowers of the dandelion, arnica, currant, balsam-root, glacier lilly, oyster plant, willow herb, and tarweed. -T. ruficaudus- has been caught in the wild with steel traps baited with meat. (Best, 1993; Nowak, 1999)
The red-tailed chipmunk is found in the central Rocky Mountain region of the United States in northwestern Montana, northern Idaho and northeastern Washington. In Canada, the range of -Tamias ruficaudus- just touches extreme southwestern Alberta and the East Kootenay valley of southern British Columbia. (Banfield, 1974; Nowak, 1999)
Biogeographic Regions: nearctic (Native )
The red-tailed chipmunk inhabits dense coniferous forests. Its numbers are greatest where shrubby growth is rich. These conditions typically occur in forest openings or edges. They can be found in forests of -Tsuga heterophylla- (western hemlock), -Thuja plicata- (western red cedar), -Pseudotsuga menziesii- (Douglas fir), and -Picea englemanni- (Englemann spruce). They are limited by open -Pinus ponderosa- (Ponderosa pine) on the western edge of their range. -T. ruficaudus- occupies bunches of stunted pine and spruce trees, and -Rhododendron- (mountain rhododendron) and -Vaccinium- (blueberry bushes) on the margins of meadows. They occur in Washington in mixed second-growth forests of -Pinus contorta- (lodgepole pine), -Larix occidentalis- (western larch), Englemann spruce, Douglas fir, -Abies grandis- (grand fir), and -Populus tremuloides- (aspen).
In northern Idaho, the red-tailed chipmunk is considered to be the most widely distributed and common chipmunk. They are plentiful higher in the mountains. In the Ponderosa pine zone, they can be found in openings with great amounts of light where boulders and low brush are present. This usually occurs along older roadways and at the lower edge of foothills. -T. ruficaudus- can be found near fallen logs and brush piles in the Canadian zone.
This species of chipmunk typically resides in burrows and on the ground, but can climb trees and bushes at times. They look for protection in old logs, crevices among rocks, and their burrows. (Best, 1993; Nowak, 1999)
Terrestrial Biomes: forest
Average lifespan
Status: wild: 8.0 years.
The red-tailed chipmunk is darker colored and larger than most chipmunks. The appearance of this chipmunk is generally similar to that of Tamias minimus (least chipmunk) and the yellow pine chipmunk. However, the red-tailed is larger and colored more brightly. In general, the pelage is rufous on the shoulders and sides, with this color fading out towards the hips. The back has a deep orange-brown tone and the rump is a shade of gray. The feet are a light brown color and the underparts are ivory. The color of the tail is rufous on the dorsal side with the ventral side a bright orange or brick red. The tail also has a black band and the tips of the hairs are yellowish. The ears are black. T. ruficaudus has five dark stripes that range from black to fuscous. The central dark stripe runs between the ears to the tail. The four pale stripes are grayish to white. The forehead is chocolate brown and the cheeks are characterized by two milky stripes separated by three brown stripes. The eye stripe is black and the stripe below the eye is brownish.
The winter pelage of T.ruficaudus is soft, dense and slightly wooly. There are two molts each year, one occurring in the spring and a second molt in the early autumn. The summer pelage differs from the winter in that it is more brightly colored.
The dental formula of the red-tailed chipmunk is 1/1 0/0 2/1 3/3=22. The skull has a short rostrum and is ovate. The postorbital processes are slender and long. The subgenus Neotamias, to which the red-tailed chipmunk belongs, is differentiated from the subgenus Tamias in that Neotamias has two premolars on each side of the upper jaw and Tamias only has one.
The red-tailed chipmunk is sexually dimorphic. Females are approximately 3% larger than males in head length and body. Males also have narrower skulls than females.
(Banfield, 1974; Best, 1993; Nowak, 1999; Smith, 1993)
Average mass: 60 g.
Other Physical Features: endothermic ; bilateral symmetry
Average mass: 75 g.
Mating in -T. ruficaudus- can occur from late February to early July but usually takes place in April or May. Pregnancy rates vary among age groups. Females that were 10 to 16 months of age were pregnant less often than older females. The overall rate of pregnancy for the population was 68 to 83% where females 10 to 16 months of age were not considered. There is only one breeding season per year, unless a litter is lost. In this case the female can enter estrus again and bear a second litter. The gestation period is 28 to 36 days. Embryos of 25 mm in head-rump length are full term. The litter size is usually three to eight young and sexual maturity is reached within the first year of life. The record of longevity in the wild for chipmunks was achieved by -T.ruficaudus-. This particular animal lived for eight years. However, fewer than 10% of the individuals survive more than 64 months. (Best, 1993; Nowak, 1999)
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average gestation period: 31 days.
Average number of offspring: 5.5.
Average age at sexual or reproductive maturity (female)
Sex: female: 335 days.
The red-tailed chipmunk (Neotamias ruficaudus) is a species of rodent in the family Sciuridae.[2] It is found in Alberta and British Columbia in Canada and Montana, Idaho and Washington in the United States.[1]
The red-tailed chipmunk is a large species with a total length of about 230 mm (9 in) including a bushy tail of 105 mm (4 in). The mass varies from about 54 g (1.9 oz) in the spring to 60 g (2.1 oz) in the fall. Females are marginally larger than males. The head is mottled grayish-brown with dark stripes above, through and below the eye. The body is basically orange-brown with five blackish stripes separated by four pale gray, tawny or cream-colored ones. The shoulders, sides, rump and flanks are tawny or buff. The underparts are creamy-white suffused with pinkish-buff. The upper side of the tail is black suffused with pinkish-buff and the underside is tawny tipped with pinkish-buff. In winter the animal's color is greyer and less tawny.[3]
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.[4][5]
The red-tailed chipmunk is native to southeastern British Columbia, southwestern Alberta, northeastern Washington, northern Idaho and western Montana. It is found at altitudes between 720 and 2,400 metres (2,360 and 7,870 ft) in coniferous forests, other woodland, forest edges, glades and bushy areas at the edge of upland meadows. It primarily lives on the ground but sometimes climb trees.[1]
The red-tailed chipmunk feeds mainly on seeds and berries and sometimes carries these in its cheek pouches.[3] Frequently eaten foods include the seeds of fir and pine, honeysuckle berries, cranberries, whortleberries, huckleberries, the seeds of locust trees and of snow brush, buckbrush, thistle, willow herb, grasses and many others types of seed. Dandelion flowers and leaves are sometimes eaten and the animal has been caught in traps baited with meat.[3] It does not hibernate but it may have periods of torpor.[3]
Breeding takes place in the late spring and summer, a litter size averaging five young born after a gestation period of about 31 days. Most nests are underground in a burrow but tree nests are occasionally used, often placed immediately underneath dense growths of dead twigs. The young first emerge from the nest when aged about 45 days.[3]
The red-tailed chipmunk (Neotamias ruficaudus) 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.
