Geographic Range
Tamias quadrivittatus
is found in east to southeastern Utah, throughout Colorado, northeastern Arizona
and northern Utah.
Habitat
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.
- Habitat Regions
- temperate
- terrestrial
- Terrestrial Biomes
- forest
- scrub forest
- mountains
Physical Description
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
.
- Other Physical Features
- endothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
Reproduction
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.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- viviparous
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
-
protecting
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-independence
-
protecting
- female
-
protecting
Lifespan/Longevity
Longevity of this species has not been reported.
Behavior
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.
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.
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.
Home Range
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.
Communication and Perception
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.
Food Habits
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
Predation
Raptors, including northern goshawks, are the main predators of Colorado chipmunks.
- Anti-predator Adaptations
- cryptic
Ecosystem Roles
Colorado chipmunks are important seed dispersers and are food for various raptors.
- Ecosystem Impact
- disperses seeds
Economic Importance for Humans: Positive
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.
Economic Importance for Humans: Negative
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.
Conservation Status
Colorado chipmunks are not listed by CITES or IUCN.
Additional Links
Contributors
Nancy Shefferly (editor), Animal Diversity Web.
Matt Hamilton (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.
- Nearctic
-
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- terrestrial
-
Living on the ground.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- scrub forest
-
scrub forests develop in areas that experience dry seasons.
- mountains
-
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
- monogamous
-
Having one mate at a time.
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- altricial
-
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
- arboreal
-
Referring to an animal that lives in trees; tree-climbing.
- fossorial
-
Referring to a burrowing life-style or behavior, specialized for digging or burrowing.
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- hibernation
-
the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.
- social
-
associates with others of its species; forms social groups.
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- carrion
-
flesh of dead animals.
- stores or caches food
-
places a food item in a special place to be eaten later. Also called "hoarding"
- cryptic
-
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
- herbivore
-
An animal that eats mainly plants or parts of plants.
- granivore
-
an animal that mainly eats seeds
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
References
Armstrond, D. 1972. Distribution of Mammals in Colorado. University of Kansas Museum of Natural History , 3: 415.
Bergstrom, B. 1988. Home Ranges of Three Species of Chipmunks(TAMIAS) as assessed by Radiotelemerty and Grid Trapping. Journal of Mammalogy , 69(1): 190-193.
Fitzgerald, J., C. Meaney, D. Armstrong. 1994. Mammals of Colorado. Denver Museum of Natural History and University Press of Colorado : 467.
Hoffmeister, D. 1986. Mammals of Arizona. The University of Arizona and Press and the Arizona Game and Fish Dept : 602.
Patterson, B. 1984. Geographic Variation and taxonomy of Colorado and Hopi Chipmunks (Genus Eutamias). Journal of Mammalogy , 65: 442-456.
Sheppard, D. 2002. "Chipmunk" (On-line ). Canadian Wildlife Service. Accessed 11/04/02 at http://www.ec.gc.ca/cws-scf/hww-fap/chipmunk/chipmunk.html .
Sullivan, R. 1996. Genetics, Ecology, and Conservation of Montane Populations of Colorado Chipmunks. Journal of Mammalogy , 77: 951-975.
Whitaker Jr., J. 2002. "Colorado Chipmunk" (On-line ). Accessed 11/04/02 at http://www.enature.com/fieldguide/showSpeciesSH.asp?curGroupID=5&shapeID=1041&curPageNum=39&recnum=MA0198 .
Biota Information System Of New Mexico (BISON). 2002. "Tamias quadrivittatus" (On-line ). Accessed 11/04/02 at http://www.cnr.vt.edu/fishex/nmex_main/species/050145.htm .