Tamias quadrivittatus is found in east to southeastern Utah, throughout Colorado, northeastern Arizona and northern Utah.

Biogeographic Regions: nearctic (Native )

endemic to a single nation

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Central and southern Colorado, northern and central New Mexico, and northeastern Arizona; elevations of 1380-3360 m (Best et al. 1994).

Colorado chipmunks are medium-sized chipmunks, with amass of about 54 g, and a length averaging 121 mm.

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.

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.

Average mass: 54 g.

Average length: 121.9 mm.

Sexual Dimorphism: sexes alike

Average mass: 70 g.

Length: 24 cm

Weight: 85 grams

• Terrestrial

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.

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.

Range elevation: 1845 to 2500 m.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: forest ; scrub forest ; mountains

Comments: Various habitats, mainly rocky areas with conifers or shrubs, Pinyon-juniper/rock associations in Arizona (Hoffmeister 1986) and Oklahoma. In New Mexico, mainly coincident with the ponderosa pine zone; also in pinyon-juniper and scrub oak-juniper habitats and in open stands or edges of spruce-fir forest; similar habitats in Colorado. Primarily terrestrial but also an adept climber. Commonly perches on rocks, stumps, or logs. See Best et al. (1994) for further details.

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

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.

Animal Foods: eggs; carrion ; insects

Plant Foods: leaves; roots and tubers; wood, bark, or stems; seeds, grains, and nuts; fruit

Foraging Behavior: stores or caches food

Primary Diet: herbivore (Granivore )

Comments: Eats seeds and fruits of various woody and herbaceous plants, and some insects. Feeds mainly on the ground but obtains some food by climbing into trees and shrubs. Stores food in underground caches.

Colorado chipmunks are important seed dispersers and are food for various raptors.

Ecosystem Impact: disperses seeds

Raptors, including northern goshawks, are the main predators of Colorado chipmunks.

Known Predators:

• raptors (Falconiformes)
• northern goshawks (Accipiter gentilis)

Anti-predator Adaptations: cryptic

Home range averages a few hectares. Overwinter survival rate is less than 33%; local extirpation or near-extirpation is a common event. See Best et al. (1994).

Colorado chipmunks are reported to give alarm calls.

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.

Communication Channels: visual ; tactile ; acoustic

Perception Channels: visual ; acoustic

Comments: Generally not active above ground during coldest winter weather. Most active above ground in morning and late afternoon.

Longevity of this species has not been reported.

Colorado chipmunks are monogamous.

Mating System: monogamous

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.

Breeding interval: These animals generally breed once per year.

Breeding season: Breeding occurs in the late winter.

Range number of offspring: 2 to 7.

Range gestation period: 1 to 2 months.

Range age at sexual or reproductive maturity (male): 4 to 5 months.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous

Average birth mass: 2.5 g.

Average number of offspring: 4.4.

Average age at sexual or reproductive maturity (female)

Sex: female: 319 days.

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.

Parental Investment: no parental involvement; altricial ; pre-fertilization (Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Protecting: Female)

Mating occurs in spring (e.g., late April-May in Colorado) throughout much of range, bimodally in February and July in southern New Mexico. Gestation lasts about 30 days. Litter size is 2-6. Young are weaned at 6-7 weeks, appear commonly in August in northern Colorado (Armstrong 1975). Perhaps generally one litter per year, but the presence of pregnant and lactating females in late summer in some areas suggests a second litter or late breeding.

Colorado chipmunks are not listed by CITES or IUCN.

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

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.

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.

Comments: Pre-1953 references to this species in some cases pertain to T. umbrinus. Bergstrom and Hoffmann (1991) found species-specific vocalizations, habitats, and bacular characters in sympatric umbrinus and quadrivittatus, but convergence in electromorphs.

Formerly included in genus Eutamias, which recently has been included in the genus Tamias (Levenson et al. 1985; Jones et al. 1992, Hoffmann et al., in Wilson and Reeder 1993). Based on patterns of variation in ectoparasites (Jameson 1999) and molecular phylogenetics (Piaggio and Spicer 2001), the North American mammal checklist by Baker et al. (2003) placed all North American chipmunks (except Tamias striatus) in the genus Neotamias.

See Sutton (1992) for a key to the species of Tamias (Neotamias).

Former subspecies rufus now is regarded as a distinct species (Patterson 1984, Best et al. 1994, Burt et al. 1994).