Tamias cinereicollisgray-collared chipmunk

Ge­o­graphic Range

Tamias cinere­icol­lis is found all through­out cen­tral and east­ern Ari­zona and cen­tral and south­west New Mex­ico in the United States (Find­ley, 1986; Nowak, 1991).

Habi­tat

These chip­munks are found pri­mar­ily in conif­er­ous forests at el­e­va­tions be­tween 1,950 abd 3,440 me­ters. They pre­fer ma­ture wood­lands and wood­lot edges, but they also in­habit areas in and around sub­ur­ban and rural homes such as around or­na­men­tal plant­i­ngs, rock­piles, out­build­ings and below pa­tios and build­ing foun­da­tions. Al­though they are mostly bur­row­ing ro­dents, they reg­u­larly climb oak trees to gain ac­cess to rooftops (Best, 1999; Cor­ri­gan, 1997; Grz­imek, 1990; Shep­pard, 1990).

  • Range elevation
    1,950 to 3,440 m
    to ft

Phys­i­cal De­scrip­tion

Tamias cinere­icol­lis are eas­ily rec­og­nized by the light and dark stripes on their back and head. They bear dis­tinct fa­cial mark­ings and have only five dark stripes on their back. There is a dis­tinct cen­tral line that ex­tends for­ward onto the head. The gray-col­lared chip­munks are cov­ered in shades of gray and share dis­tinc­tive pat­terns of black, pale gray, and buff stripes. Tamias cinere­icol­lis is one of the smaller chip­munks. It has a total length be­tween 208 and 242 mm, with males mea­sur­ing slightly smaller than fe­males. Weights range be­tween 55 and 70 g. It has a rel­a­tively long tail, com­pris­ing from 90 to 109 mm of the total length of the an­i­mal (Best, 1999; Grz­imek, 1990; Shep­pard, 1990).

  • Sexual Dimorphism
  • female larger
  • Range mass
    55 to 70 g
    1.94 to 2.47 oz
  • Range length
    208 to 242 mm
    8.19 to 9.53 in

Re­pro­duc­tion

Mat­ing oc­curs two times a year, dur­ing early spring and again dur­ing the sum­mer or early fall. There is a 30 to 31 day ges­ta­tion pe­riod. Two to five young are born in the spring (early May) and again be­tween Au­gust and Oc­to­ber. They are born naked and blind. Young can eat solid foods by the age of 36 to 40 days, and are weaned by the age of 41 to 45 days. The young are sex­u­ally ma­ture within one year and adults may live for up to three years. Young ap­pear for the first time above ground when they are 2/3 full size. The ba­bies are reared by the mother with­out any help from the fa­thers (Best, 1999; Cor­ri­gan, 1997; Shep­pard, 1990).

  • Breeding interval
    These animals usually breed twice yearly.
  • Breeding season
    This species breeds in the spring as well as in summer or early fall.
  • Range number of offspring
    2 to 5
  • Average gestation period
    30-31 days
  • Range weaning age
    41 to 45 days
  • Average time to independence
    45 days
  • Average age at sexual or reproductive maturity (female)
    1 years
  • Average age at sexual or reproductive maturity (male)
    1 years

Be­hav­ior

Tamias cinere­icol­lis is most ac­tive dur­ing the early morn­ing and late af­ter­noon. These chip­munks are gen­er­ally soli­tary and pro­tect their ter­ri­to­ries ex­cept dur­ing courtship, or when the young are de­vel­op­ing. Pop­u­la­tions of chip­munks av­er­age be­tween 2 and 4 an­i­mals per acre. The home ranges often over­lap among in­di­vid­u­als, and the home ranges of adults are larger than those of ju­ve­niles. The home ranges of fe­males tend to be smaller than those of males.

With the onset of cold weather, chip­munks enter a rest­less hi­ber­na­tion dur­ing late fall or early win­ter and are rel­a­tively in­ac­tive dur­ing the win­ter months. Some in­di­vid­u­als, how­ever, oc­ca­sion­ally come out on warm, sunny days dur­ing the win­ter. By early March, most gray-col­lared chip­munks have emerged from hi­ber­na­tion.

Male T. cinere­icol­lis are the first to emerge in the spring. The fe­males emerge one or two weeks later. Once fe­males emerge, breed­ing takes place near a fe­male's bur­row. Com­pe­ti­tion oc­curs be­tween males for fe­males, and a male may mate with more than one fe­male dur­ing a mat­ing sea­son.

The bur­rows of T. cinere­icol­lis are well-hid­den near build­ings (such as base­ments and garages), gar­dens, stumps, wood­piles or brush­piles. The bur­row en­trance is usu­ally about 2 inches in di­am­e­ter. There are no ob­vi­ous mounds around the bur­row en­trance be­cause these chip­munks carry the dirt in their cheek pouches and scat­ters it on the ground away from the bur­row to make the bur­row en­trance less con­spic­u­ous.

A chip­munk's main tun­nel is be­tween 20 and 30 feet in length, but com­plex bur­row­ing sys­tems occur where cover is sparse. Bur­row sys­tems nor­mally in­clude a nest­ing cham­ber, one or two food stor­age cham­bers, var­i­ous side pock­ets con­nect­ing to the main tun­nel, and sep­a­rate es­cape tun­nels.

(Cor­ri­gan, 1997; Shep­pard, 1990).

  • Range territory size
    3.33 (high) m^2

Home Range

The av­er­age ter­ri­tory of a chip­munk is about 1/4 to 1/2 acre, but an adult usu­ally only de­fends an area about fifty feet around the bur­row en­trance (Cor­ri­gan, 1997; Shep­pard, 1990).

Com­mu­ni­ca­tion and Per­cep­tion

Food Habits

Tamias cinere­icol­lis spends much of its day col­lect­ing and stor­ing seeds, which are its most im­por­tant source of food. These chip­munks often for­age on the ground and they eas­ily climb trees and shrubs to har­vest nuts and fruits.

The diet of T. cinere­icol­lis con­sists of var­i­ous kinds of nuts, berries, and seeds. Mush­rooms, cherry and plum pits, in­sects, worms and car­rion are also con­sumed. Rare in­stances of T. cinere­icol­lis prey­ing on birds or small mam­mals have been ob­served.

When these chip­munk pre­pare food for stor­age, they holds the seeds in their dex­ter­ous front paws and with their spe­cial­ized in­cisors. Their in­cisors are es­pe­cially long and di­rected for­ward. Tamias cinere­icol­lis re­moves seeds from pods with its in­cisors, then uses its tongue to shift the seeds back­ward. It stuffs the seeds be­tween its teeth and in­side of its cheekpouches. The ca­pac­ity of these cheekpouches in­creases with ma­tu­rity. When they cheek pouches are full, a chip­munk de­posits the seeds in its nest or buries them in shal­low holes.

After hi­ber­na­tion, gray-col­lared chip­munks dili­gently search the ground for any seeds that re­main from the pre­vi­ous sum­mer. Since these are usu­ally un­com­mon, T. cinere­icol­lis may eat young leaves and shoots until new fruit and seeds be­come avail­able (Cor­ri­gan, 1997; Schultz, 1995; Shep­pard, 1990).

  • Animal Foods
  • birds
  • mammals
  • Plant Foods
  • leaves
  • roots and tubers
  • wood, bark, or stems
  • seeds, grains, and nuts

Pre­da­tion

Preda­tors in­clude as hawks, weasels, coy­otes, martens, foxes, and snakes. Fight­ing dur­ing the breed­ing sea­son is also a source of in­jury and death for many gray-col­lared chip­munks.

The most sig­nif­i­cant de­crease in T. cinere­icol­lis pop­u­la­tions oc­curs dur­ing pe­ri­ods of food short­age such as when there is seed crop fail­ure and the chip­munk doesn't have enough food stored for its hi­ber­na­tion. Tamias cinere­icol­lis de­pends on this food dur­ing the win­ter when it doesn't have ac­cess to seeds that are cov­ered by snow, etc. (Shep­p­pard, 1990).

Ecosys­tem Roles

Since chip­munks prey upon in­sects, their food habits in­flu­ence the growth of var­i­ous plants. Gray-col­lared chip­munks are also im­por­tant in the dis­per­sal of seeds be­cause of their habit of stor­ing them be­neath the layer of de­cay­ing veg­e­ta­tion on the for­est floor. In this way, T. cinere­icol­lis as­sist in the spread of shrubs, trees, and other plants. As a prey species, pop­u­la­tions of T. cinere­icol­lis may have some im­pact upon preda­tor pop­u­la­tions. (Cor­ri­gan, 1997; Shep­pard, 1990).

  • Ecosystem Impact
  • disperses seeds

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

These an­i­mals are not re­ported to have a pos­i­tive im­pact on human economies.

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Chip­munks can be se­ri­ous de­struc­tive pests when they be­come nu­mer­ous around homes and gar­dens. The bur­row­ing ac­tiv­ity of chip­munks can cause sig­nif­i­cant struc­tural dam­age by un­der­min­ing foun­da­tions, con­crete pa­tios and steps, re­tain­ing walls and side­walks. They may also be de­struc­tive to gar­dens when they dig up and eat bulbs and seeds or at­tack gar­den fruits. When they be­come over-abun­dant, gray-col­lared chip­munks can pre­vent nor­mal re­for­esta­tion of some trees, es­pe­cially pines, by eat­ing their seeds. When this oc­curs, they have to be trapped by hu­mans.

Ro­dents, such as T. cinere­icol­lis, have also been as­so­ci­ated as being car­ri­ers of the han­tavirus in the south­west­ern United States. Human in­fec­tion may occur when in­fec­tive saliva or exc­reta are in­haled as aerosols pro­duced di­rectly from the an­i­mal. Per­sons have also be­come in­fected after being bit­ten by ro­dents (Cor­ri­gan, 1997; Health­touch, 1997; Shep­pard, 1990).

  • Negative Impacts
  • injures humans
    • bites or stings
    • carries human disease
  • crop pest
  • household pest

Con­ser­va­tion Sta­tus

Gray-col­lared chip­munks are not in any dan­ger of going ex­tinct any time soon. In fact, this species ex­pe­ri­ences only tiny fluc­tu­a­tions in its pop­u­la­tion from year to year. These fluc­tu­a­tions have been at­trib­uted to preda­tors such as hawks, weasels, coy­otes, martens, foxes, and snakes. Fight­ing dur­ing the breed­ing sea­son is also a source of in­jury and death for many gray-col­lared chip­munks.

The most sig­nif­i­cant de­crease in T. cinere­icol­lis pop­u­la­tions oc­curs dur­ing pe­ri­ods of food short­age such as when there is seed crop fail­ure and chip­munks doesn't have enough food stored for hi­ber­na­tion. T. cinere­icol­lis de­pends on stored food dur­ing the win­ter when it doesn't have ac­cess to seeds that are cov­ered by snow, etc. (Shep­p­pard, 1990).

Other Com­ments

Gray-col­lared chip­muinks, along with many other chip­munks, have charm­ing per­son­al­i­ties. They charm campers and hik­ers with their small size, their bold­ness in search of food, and their con­stant ac­tiv­ity. In fact, they are not hard to ap­proach at all. They are eas­ily per­suaded to ac­cept seeds or nuts from a per­son's hands (Shep­pard, 1990).

Con­trib­u­tors

Nancy Shef­ferly (ed­i­tor), An­i­mal Di­ver­sity Web.

Can­dace T. Smith (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor.

Glossary

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.

World Map

acoustic

uses sound to communicate

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.

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
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.

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

fossorial

Referring to a burrowing life-style or behavior, specialized for digging or burrowing.

granivore

an animal that mainly eats seeds

herbivore

An animal that eats mainly plants or parts of plants.

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.

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).

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

suburban

living in residential areas on the outskirts of large cities or towns.

tactile

uses touch to communicate

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.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

urban

living in cities and large towns, landscapes dominated by human structures and activity.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

Ref­er­ences

Cor­ri­gan, R. "Chip­munks." Pur­due Uni­ver­sity. http://​www.​entm.​purdue.​edu/​entomology/​urbancenter/​pubs/​chips.​html (1 Dec. 1997)

Find­ley, J.S. 1987. The Nat­ural His­tory of New Mex­i­can Mam­mals. Uni­ver­sity of New Mex­ico Press, Al­bu­querque.

Grz­imek, B. 1990. En­cy­clo­pe­dia of Mam­mals. Mc­Graw-Hill Pub­lish­ing, Co. Vol 3. pp. 78-82

"Han­tavirus In­fec­tion-South­west United States." Health­touch On­line. http://​www.​healthtouch.​com/​level1/​leaflets/​cdc/​cdc016.​htm (1 Dec. 1997)

Nowak, R.M. 1991. Walker's Mam­mals of the World. Fifth Edi­tion. Johns Hop­kins Uni­ver­sity Press, Bal­ti­more. pp. 586-589

Shep­pard, D. 1990. "Chip­munk." Cana­dian Wildlife Ser­vice Hin­ter­land Who's Who. http://​www.​ec.​gc.​ca/​cws-scf/​hww-fap/​chipmunk/​chipmunk.​html (1 Dec. 1997)

Best, T. 1999. Gray-col­lared chip­munk (Tamias cinereiol­lis). Pp. 362-363 in D Wil­son, S Ruff, eds. The Smith­son­ian Book of North Amer­i­can Mam­mals. Wash­ing­ton and Lon­don: The Smith­son­ian In­sti­tu­tion Press.