David E. Williams State Director USDA-APHIS- CHIPMUNKS Animal Damage Control Lincoln, Nebraska 68501 Robert M. Corrigan Staff Specialist Vertebrate Pest Management Purdue University West Lafayette, Indiana 47907 Fig. 1. Eastern chipmunk, Tamias striatus Damage Prevention and Frightening Toxicants Control Methods Not effective. None are federally registered. Check with local extension agents or a Exclusion Repellents USDA-APHIS-ADC personnel for Rodent-proof construction will Area repellents. Naphthalene (moth possible Special Local Needs 24(c) exclude chipmunks from structures. flakes or moth balls) may be effec- registrations. tive if liberally applied in confined Fumigants Use 1/4-inch (0.6-cm) mesh hardware places. cloth to exclude chipmunks from Generally impractical. gardens and flower beds. Taste repellents. Repellents containing bitrex, thiram, or ammonium soaps Trapping Habitat Modification of higher fatty acids applied to Rat-sized snap traps. Store food items, such as bird seed flower bulbs, seeds, and vegetation and dog food, in rodent-proof (not for human consumption) may Live (box or cage) traps. control feeding damage. containers. Glue boards. Ground covers, shrubs, and wood piles Shooting should not be located adjacent to structure foundations. Small gauge shotguns or .22-caliber rifles. PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994 Cooperative Extension Division Institute of Agriculture and Natural Resources University of Nebraska - Lincoln United States Department of Agriculture Animal and Plant Health Inspection Service Animal Damage Control B-13 Great Plains Agricultural Council Wildlife Committee 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. B-14 Adult least chipmunks mate over a Legal Status Repellents period of 4 to 6 weeks from April to Naphthalene flakes (“moth flakes”) mid-July. Least chipmunks produce 1 Chipmunks are not protected by fed- may repel chipmunks from attics, litter of 2 to 7 young in May or June. eral law, but state and local regulations summer cabins, and storage areas Occasionally a second litter is pro- may apply. Most states allow land- when applied liberally (4 to 5 pounds duced in the fall. owners or tenants to take chipmunks when they are causing or about to of naphthalene flakes per 2,000 square 2 Chipmunk pups appear above ground cause damage. Some states, (for feet [1.0 to 1.2 kg/100 m ]). Use cau- when they are 4 to 6 weeks old — 2/3 example, Georgia, North Carolina, and tion, however, in occupied buildings, the size of an adult. Young will leave Arkansas) require a permit to kill as the odor may also be objectionable the burrow at 6 to 8 weeks. nongame animals. Other states are or irritating to people or pets. Population densities of chipmunks are currently developing laws to protect There are currently no federally regis- typically 2 to 4 animals per acre (5 to all nongame species. Consult your lo- tered repellents for controlling rodent 10/ha). Eastern chipmunk population cal conservation agency or USDA- damage to seeds, although some states densities may be as high as 10 animals APHIS-ADC personnel for the legal have Special Local Needs 24(c) regis- per acre (24/ha), however, if sufficient status of chipmunks in your state. trations for this purpose. Taste repel- food and cover are available. Home lents containing bitrex, thiram, or ranges often overlap among Damage Prevention and ammonium soaps of higher fatty acids individuals. Control can be used to protect flower bulbs, seeds, and foliage not intended for hu- Food Habits Exclusion man consumption. Multiple applica- tions of repellents are required. Chipmunks should be excluded from The diet of chipmunks consists prima- Repellents can be expensive and usu- buildings wherever possible. Use hard- rily of grains, nuts, berries, seeds, ally do not provide 100% reduction in ware cloth with 1/4-inch (0.6-cm) mushrooms, insects, and carrion. damage to horticultural plantings. mesh, caulking, or other appropriate Although chipmunks are mostly materials to close openings where they Toxicants ground-dwelling rodents, they regu- could gain entry. larly climb trees in the fall to gather There are no toxic baits registered for nuts, fruits, and seeds. Chipmunks Hardware cloth may also be used to controlling chipmunks. Baits that are cache food in their burrows through- exclude chipmunks from flower beds. used against rats and mice in and out the year. By storing and scattering Seeds and bulbs can be covered by around homes will also kill chipmunks seeds, they promote the growth of 1/4-inch (0.6-cm) hardware cloth and although they are not labeled for such various plants. the cloth itself should be covered with use and cannot be recommended. soil. The cloth should extend at least 1 Moreover, chipmunks that die from Chipmunks also prey on young birds foot (30 cm) past each margin of the consuming a toxic bait inside struc- and bird eggs. Chipmunks themselves planting. Exclusion is less expensive in tures may create an odor problem for serve as prey for several predators. the long run than trapping, where several days.