Tamias quadrivittatus
Colorado chipmunk

Tamias quadrivittatus is found in east to southeastern Utah, throughout Colorado, northeastern Arizona and northern Utah. (Bergstrom, 1988; "Tamias quadrivittatus", 2002; Sullivan, 1996; Whitaker Jr., 2002)

Colorado chipmunks are most common in ponderosa forest but may also be abundant in mixed coniferous forest and woodland. A few are found in spruce-fir areas, but Tamias minimus is the more common chipmunk there. At lower elevations, in scattered pinyon-juniper woodland, T. quadrivittatus. may be fairly common, especially if rock outcrops are available. In the Organ mountains, the southern subspecies of the Colorado chipmunk is most common around Aguirre Springs at elevations ranging between 1845 and 2225 m. The species also occurs in the Oscura Mountains at elevations ranging from 2393 to 2500 m, where vegetation is believed to be similar to the Organs. ("Tamias quadrivittatus", 2002; Fitzgerald, et al., 1994; Sullivan, 1996)

These chipmunks are strong tree-climbers, but they spend most of their time among fallen logs, rock piles, and on the ground. They may be found among rock outcrops to elevations nearly in the spruce-fir forest. In Utah, these chipmunks have been found in association with broken rock or rock crevices in the pinyon-juniper community. ("Tamias quadrivittatus", 2002; Fitzgerald, et al., 1994; Sullivan, 1996)

Colorado chipmunks are medium-sized chipmunks, with amass of about 54 g, and a length averaging 121 mm. (Patterson, 1984; Sullivan, 1996)

The pelt is mostly orange, although the head is cinnamon colored, with shades of gray with white color on the belly, and yellowish-brown on the sides. These animals have 3 median stripes on their backs, which are black with yellowish-orange margins, and have outer stripes that are brown. Shoulders are gray, the thighs and rump are cinnamon. The tail is black tipped, white-bordered, and tawny underneath. Their ears are blackish in front, whitish behind. (Patterson, 1984; Sullivan, 1996)

Distinction from similar species (Tamias rufus) can be found in the baculum size. Studies have shown that the baculum is larger in dimensions in T. quadrivittatus. (Patterson, 1984; Sullivan, 1996)

Colorado chipmunks are monogamous. (Whitaker Jr., 2002)

Breeding takes place in spring. Gestation lasts between 29 and 60 days. One litter of 2 to 7 young is produced and the young will be fully grown by July to August. Presence of some small young in October may indicate an occasional second litter, although one litter per year is thought to be more typical. ("Tamias quadrivittatus", 2002; Hoffmeister, 1986; Whitaker Jr., 2002)

No information on the parental care of this species was found. However, in general, ground dwelling sciurids are altricial. They are born in the burrow, where the mother cares for them, providing them with milk, grooming, and protection, until they are capable of dispersing. Although no information is available, because this species is monogamous, it is possible that the male plays some role in the parental care.

Longevity of this species has not been reported.

Tamias quadrivittatus is active in the early morning and late afternoon. They give a short bark to warn when they are alarmed. They are more arboreal than most chipmunks, and they tend to occupy coniferous areas. (Bergstrom, 1988; Whitaker Jr., 2002)

They have been spotted eating seed at the tops of spruce trees. In Colorado, this chipmunk is often associated with the more abundant species T. minimus, which occupies meadows. In New Mexico, T. quadrivittatus occurs at higher elevations, in areas of ponderosa pine, Douglas fir, and aspen, and cliff chipmunks occur in lower elevation areas with pinyon-pine and juniper woods. (Bergstrom, 1988; Whitaker Jr., 2002)

Tamias quadrivittatus maintains male-female pairs during the breeding season. They forage near their burrows, returning frequently to their nesting sites to cache food. They are generally active by day. During winter months they retreat to nests in trees, logs, or underground burrows to hibernate. (Bergstrom, 1988; Whitaker Jr., 2002)

Home range for adult females is 2.6 acres; and for adult males the range is 3.2 acres. The home range of juveniles is anywhere from around 1 to 2.5 acres. ("Tamias quadrivittatus", 2002; Hoffmeister, 1986)

Colorado chipmunks are reported to give alarm calls. (Whitaker Jr., 2002)

In addition to accoustic communication, as diurnal mammals, members of this species are likely to use some visual communication, such as body postures. Tactile communication undoubtedly occurs between mates, parents and their offspring, and rivals. There are probably some chemical cues used also.

Colorado chipmunks are herbivorous. Their diet consists of seeds and berries, but they will also feed on insects, bird eggs, and carrion. Seed and berry types include ricegrass, juniper, cliffrose, skunkbush, mountain mahogany, and squawberry in July and August; Russian thistle, pinyon, oak, and Indian ricegrass in September and October. They are known to cache their food. With good climbing ability, T. quadrivittatus will search in between rocks, bushes and in trees for food. They depend upon free water sources. (Armstrond, 1972; "Tamias quadrivittatus", 2002)

Raptors, including northern goshawks, are the main predators of Colorado chipmunks. ("Tamias quadrivittatus", 2002)

Colorado chipmunks are important seed dispersers and are food for various raptors. ("Tamias quadrivittatus", 2002)

Although very cute animals, Colorado chipmunks are not known to have a direct economic importance to humans. However, through their seed caching, they help the growth of plants which normally have difficulty germinating on the surface.

These animals are not directly harmful to the economic activities of humans. However, if populations are large, they may impact forest regrowth by eating seeds.

Colorado chipmunks are not listed by CITES or IUCN.