a Chipmunks are generally solitary ex- Identification cept during courtship or when rearing Fifteen species of native chipmunks of young. the genus Eutamias and one of the The least chipmunk inhabits low sage- genus Tamias are found in North brush deserts, high mountain conifer- America. The eastern chipmunk ous forests, and northern mixed (Tamias striatus) and the least chip- hardwood forests. munk (Eutamias minimas), discussed here, are the two most widely distrib- The home range of a chipmunk may uted and notable species. Behavior and be up to 1/2 acre (0.2 ha), but the adult damage is similar among all species of only defends a territory about 50 feet native chipmunks. Therefore, damage (15.2 m) around the burrow entrance. control recommendations are similar Chipmunks are most active during the for all species. early morning and late afternoon. Chipmunk burrows often are well- The eastern chipmunk is a small, b brownish, ground-dwelling squirrel. It hidden near objects or buildings (for is typically 5 to 6 inches (13 to 15 cm) example, stumps, wood piles or brush long and weighs about 3 ounces (90 g). piles, basements, and garages). The It has two tan and five blackish longi- burrow entrance is usually about 2 tudinal stripes on its back, and two tan inches (5 cm) in diameter. There are no and two brownish stripes on each side obvious mounds of dirt around the en- of its face. The longitudinal stripes end trance because the chipmunk carries at the reddish rump. The tail is 3 to 4 the dirt in its cheek pouches and scat- inches (8 to 10 cm) long and hairy, but ters it away from the burrow, making it is not bushy (Fig. 1). the burrow entrance less conspicuous. The least chipmunk is the smallest of In most cases, the chipmunk’s main the chipmunks. It is typically 3 2/3 to tunnel is 20 to 30 feet (6 m to 9 m) in 4 1/2 inches (9 to 11 cm) long and length, but complex burrow systems weighs 1 to 2 ounces (35 to 70 g). The occur where cover is sparse. Burrow systems normally include a nesting color varies from a faint yellowish gray Fig. 2. Range of the eastern (a) and least chip- with tawny dark stripes (Badlands, munk (b) in North America. chamber, one or two food storage South Dakota) to a grayish tawny chambers, various side pockets con- nected to the main tunnel, and sepa- brown with black stripes (Wisconsin larger than the chipmunk, has a rate escape tunnels. and Michigan). The stripes, however, bushier tail and lacks the longitudinal continue to the base of the tail on all stripes of the chipmunk. Red squirrels With the onset of cold weather, chip- least chipmunks. spend a great deal of time in trees, munks enter a restless hibernation and while chipmunks spend most of their Chipmunks are often confused with are relatively inactive from late fall time on the ground, although they can thirteen-lined ground squirrels through the winter months. Chip- climb trees. (Spermophilus tridecemlineatus), also munks do not enter a deep hibernation called “striped gophers,” and red as do ground squirrels, but rely on the squirrels (Tamiasciurus hudsonicus). The Range cache of food they have brought to thirteen-lined ground squirrel is yel- their burrow. Some individuals be- lowish, lacks the facial stripes, and its The eastern chipmunk’s range in- come active on warm, sunny days dur- tail is not as hairy as the chipmunk’s. cludes most of the eastern United ing the winter. Most chipmunks As this squirrel’s name implies, it has States. The least chipmunk’s range emerge from hibernation in early 13 stripes extending from the shoulder includes most of Canada, the US March. to the tail on each side and on its back. Rocky Mountains, the Great Basin, and Eastern chipmunks mate two times a When startled, a ground squirrel car- parts of the upper Midwest (Fig. 2). year, during early spring and again ries its tail horizontally along the during the summer or early fall. There ground; the chipmunk carries its tail Habitat and General is a 31-day gestation period. Two to 5 upright. The thirteen-lined ground Biology young are born in April to May and squirrel’s call sounds like a high- again in August to October. The young pitched squeak, whereas chipmunks Eastern chipmunks typically inhabit are sexually mature within 1 year. have a rather sharp “chuck-chuck- mature woodlands and woodlot edges, Adults may live up to 3 years. chuck” call. The red squirrel is very vo- but they also inhabit areas in and cal and has a high-pitched chatter. It is around suburban and rural homes.

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Aluminum phosphide, however, can- stores, pest control companies, or munks are quite destructive when it not be used in, under, or even near rented from local animal shelters. comes to their burrowing activities occupied buildings because there is a around structures. This damage war- Check traps frequently to remove danger of the fumigant seeping into rants an investment in control to pro- captured chipmunks and release any buildings. tect structural integrity of stairs, patios, nontarget animals caught in them. and foundations. Their consumption Gas cartridges are registered for the Avoid direct contact with trapped of seeds, flower bulbs, fruit, and veg- control of burrowing rodents and are chipmunks. Transport and release live- etables is often a nuisance. available from garden supply centers, trapped chipmunks several miles from hardware stores, seed catalogs, or the the point of capture (in areas where USDA-APHIS-ADC program. Chip- they will not bother someone else), or Acknowledgments munk burrows may have to be euthanize by placing in a carbon diox- We would like to thank all the USDA-APHIS- enlarged to accommodate the com- ide chamber. ADC wildlife biologists who provided mercially or federally produced gas information on chipmunks pertinent to their Common rat snap traps can be used to cartridges. Gas cartridges should not locality. Kathleen LeMaster and Dee Anne kill chipmunks if these traps are iso- Gillespie provided technical assistance. be used under or around buildings or lated from children, pets, or wildlife. near fire hazards since they burn with Figure 1 from Schwartz and Schwartz (1981). They can be set in the same manner as an open flame and produce a tremen- Figure 2 from Burt and Grossenheider (1976). live traps but hard baits should be tied dous amount of heat. Carbon monox- to the trap trigger. Prebait snap traps ide and carbon dioxide gases are by not setting the trap until the animal For Additional produced while the cartridges burn; has been conditioned to take the bait Information thus, the rodents die from without disturbance for 2 to 3 days. asphyxiation. Bennett, G. W., J. M. Owens, and R. M. Small amounts of extra bait may be Corrigan. 1988. Truman’s scientific guide to Trapping placed around the traps to make them pest control operations. Purdue Univ./ more attractive. Set the snap traps per- Edgell Commun. Duluth, Minnesota. 539 Trapping is the most practical method pendicular to the chipmunk’s pathway pp. of eliminating chipmunks in most or in pairs along travel routes with the Burt, W. H., and R. P. Grossenheider. 1976. A home situations. Live-catch wire-mesh triggers facing away from each other. field guide to the mammals. Houghton traps or common rat snap traps can be Set the trigger arm so that the trigger Mifflin Co., Boston. 289 pp. used to catch chipmunks. Common is sensitive and easily sprung. Corrigan, R. M., and D. E. Williams. 1988. live-trap models include the Toma- Chipmunks. ADC-2 leaflet, Coop. Ext. Serv., hawk (Nos. 102, 201) and Havahart To avoid killing songbirds in rat snap Purdue Univ., West Lafayette, Indiana. in (Nos. 0745, 1020, 1025) traps. Check the traps, it is advisable to place the traps coop. with the US Dept. Agric. 2 pp. Supplies and Materials section for under a small box with openings that Dudderar, G. 1977. Chipmunks and ground additional manufacturers of live-catch allow only chipmunks access to the squirrels. Ext. Bull. E-867, Michigan State traps. baited trap. The box must allow Univ., Lansing, Michigan. 1 p. enough clearance so the trap operates Eadie, W. R. 1954. Animal control in field, farm, A variety of baits can be used to lure properly. Conceal snap traps that are and forest. The Macmillan Co., New York. chipmunks into live traps, including set against structures by leaning 257 pp. peanut butter, nutmeats, pumpkin or boards over them. Small amounts of Gunderson, H. L., and J. R. Beer. 1953. The sunflower seeds, raisins, prune slices, bait can be placed at the openings as mammals of Minnesota. Univ. Minnesota or common breakfast cereal grains. Press. Minneapolis. 190 pp. an attractant. Place the trap along the pathways Hoffmeister, D. F., and C. O. Mohr. 1957. A where chipmunks have been seen fre- Shooting fieldbook of Illinois mammals. Nat. Hist. quently. The trap should be securely Surv. Div. Urbana, Illinois. 233 pp. Where shooting is legal, use a small- placed so there is no movement of the gauge shotgun or a .22-caliber rifle Marsh, R. E., and W. E. Howard. 1990. trap prematurely when the animal with bird shot or C.B. cap loads. Chip- Vertebrate pests. Pages 771-831 in A. Mallis enters. Trap movement may prema- ed., Handbook of pest control. 7th ed. munks are nervous and alert, so they turely set off the trap and scare the Franzak and Foster Co. Cleveland, Ohio. make difficult targets. The best time to chipmunk away. A helpful tip is to Schwartz, C. W., and E. R. Schwartz. 1981. The attempt shooting is on bright sunny “prebait” the trap for 2 to 3 days by wild mammals of Missouri. The Univ. days during the early morning. wiring the trap doors open. This will Missouri Press. Columbia. 356 pp. condition the chipmunk to associate the new metal object in its territory Economics of Damage Editors with the new free food source. Set the and Control Scott E. Hygnstrom trap after the chipmunk is actively Robert M. Timm feeding on the bait in and around the The majority of chipmunk damage in- Gary E. Larson trap. Live traps can be purchased from volves minimal economic loss (under local hardware stores, department $200). Homeowners report that chip-

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