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Eastern chipmunks are extremely vocal and produce a variety of chips, trills and calls to alert others to the presence of predators or for territory defense. Territorial calls lead to aggressive behavior when another individual is present. High intense chases establish hierarchies among groups of males competing for access to females, individuals display aggressive and submissive postures during these behaviors. Sniffing hindquarters and touching noses provides chemical signals during these interactions. Alarm calls can be costly and the benefits must outweigh the costs to justify such behavior. Eastern chipmunks give three distinct calls: chipping, chucking and trilling. Chipping and chucking are repeated calls lasting up to thirty minutes. Trills are shorter in duration and are given during pursuit by a predator. The other calls are typically given when a predator is spotted.
Eastern chipmunks react to alarm calls by altering their foraging behavior and becoming more alert. After an alarm call, they expend greater energy and spend more time exposed at feeding stations because they decrease the amount of food carried to caches after hearing the call. Eastern chipmunks increase vigilance, run shorter more direct distances and delay emergence from burrows after hearing an alarm call, which suggest that the calls directly affected behavior. Trill vocalizations are complicated and more difficult to understand than the other two types of calls. Adult females are most likely to trill when close (10 m from the burrow) to relatives. Females do not disperse as far as males and have more relatives living close to their burrows. Juvenile females trill at a lower rate than adults, this may indicate their higher predation risk or smaller fitness gain. Males trill farther from the burrow, 100 m or greater. This could be because males are uncertain of kinship and trilling would put an individual at higher risk. Trilling occurs in all active seasons, not just during juvenile emergence, which discounts the hypothesis that trilling is a mechanism of parental care. The primary function of trill calls is likely to warn nearby relatives of predators. This increases an individual’s overall fitness by helping related individuals.
Communication Channels: acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
Eastern chipmunks are listed as a species of Least Concern according to the IUCN Red List.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Some Sciurids cause destruction to crops in gardens, fields and in food storage areas. Eastern chipmunks are not noted for causing this type of damage.
Negative Impacts: crop pest
Eastern chipmunks are not significantly important to the economy. Eastern chipmunks eat insects and may be helpful in controlling the population of some pest species. They are also easily tamed and can make unique pets.
Positive Impacts: pet trade ; controls pest population
Eastern chipmunks are primarily 'larder hoarders'. Seeds stored in this way cannot establish seedlings and are not beneficial to plant dispersal. However, their occasional scatter-hoarding behavior can be beneficial in seedling establishment. They also are important to spore dispersal for different kinds of fungi. Because of their abundance, chipmunks are a valuable prey item for a variety of species.
Ecosystem Impact: disperses seeds
Dietary staples include fruit, seeds and nuts. This is supplemented with insects, earthworms, slugs, bird’s eggs and mushrooms. Food is transported within cheek pouches located on either side of the mouth. Eastern chipmunks demonstrate food caching behavior throughout the year, but are particularly active in the early autumn to prepare for winter. Eastern chipmunks scatter-hoarder and will leave caches throughout their home range or in one of the rooms their burrow. They do not have the fat stores to hibernate, but instead enter periods of torpor. Chipmunks may arise frequently to feed and during mild winter weather they may forage above ground.
Animal Foods: eggs; insects; terrestrial worms
Plant Foods: seeds, grains, and nuts; fruit
Other Foods: fungus
Foraging Behavior: stores or caches food
Primary Diet: herbivore (Granivore ); omnivore
Eastern chipmunks are widely distributed throughout the eastern United States and southeastern Canada. Their range extends from Nova Scotia, east to Saskatchewan and south to Oklahoma, where they occupy the eastern part of the state. Their range includes eastern Louisiana and the Florida Panhandle. This species does not occupy the peninsula of Florida or the coastal plains region, from Florida to North Carolina. They are not native to Newfoundland, but have been introduced.
Biogeographic Regions: nearctic (Introduced , Native )
In the western portion of their range, eastern chipmunks inhabit wooded areas, river valleys and are interspersed in habitats distant from deciduous forests. This ground dwelling mammal inhabits open deciduous forests where cover is readily available in the form of stumps, logs or rocky outcrops. Their prime habitat is mature beech-maple forests, but they will occupy bushy areas and coniferous forests, however, swampy sites are avoided.
Terrestrial Biomes: forest
Other Habitat Features: urban ; suburban ; agricultural
Most eastern chipmunks survive less than two years, but there are accounts of chipmunks living up to eight years.
Range lifespan
Status: wild: 2 to 8 years.
Average lifespan
Status: wild: 8 years.
Average lifespan
Status: wild: 3.0 years.
Average lifespan
Status: captivity: 8.0 years.
Eastern chipmunks are small rodents with grayish to reddish brown fur and a distinguishing yellowish to reddish patch on their rumps. Their pelage color and pattern varies by geography. Their underparts are white. Their sides and back have five dark stripes; the longest stripe occurs along their midline. Between their dark lateral stripes, there is a narrow white band. Light and dark stripes occur on their face around their eyes. Their tail is hairy, but not bushy and is somewhat flattened. Their rounded ears measure less than 20 mm. Their forefeet have four toes and their hindfeet have five. Eastern chipmunks have large cheek pouches located on either side of their mouth. The stripe along their body distinguishes them from all other rodents except least chipmunks. However, least chipmunks' stripes extend to the base of their tail, whereas, eastern chipmunks' stripes stop before their rump patch. Eastern chipmunks are noticeably larger than least chipmunks, which helps to distinguish between the two species.
Range mass: 66 to 115 g.
Range length: 255 to 266 mm.
Other Physical Features: endothermic ; bilateral symmetry
Average basal metabolic rate: 0.813 W.
Eastern chipmunks are prey for most diurnal predators including weasels, felids and domestic dogs and cats. Large raptors including red-tailed hawks and goshawks also prey on chipmunks.
Known Predators:
Eastern chipmunks are polygamous. During a brief estrous period, females mate with multiple males. Typically females in estrous stay within their home range and males come from outside areas to mate. On average, males travel 170 meters from their burrow to mate.
Mating System: polygynous
Eastern chipmunks produce two litters per year; one in early spring and one in midsummer. Their gestation period lasts 35 days. Litters consist of 2 to 5 altricial young, which are born blind and hairless in underground nests. Litter sizes are dependent on resource availability and the age of the mother.
Breeding interval: Eastern chipmunks have 2 breeding seasons.
Breeding season: One of their breeding seasons begins in February and lasts until April and the second begins in June and ends in August.
Range number of offspring: 2 to 5.
Average gestation period: 35 days.
Average weaning age: 40 days.
Average time to independence: 2 months.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average birth mass: 3.4 g.
Average gestation period: 31 days.
Average number of offspring: 5.
Average age at sexual or reproductive maturity (male)
Sex: male: 228 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 187 days.
At birth, young weigh just 3 grams. The neonates are weaned 40 days after birth. After weaning, females move to a new burrow, leaving their young in the natal burrow until they disperse. Young become independent two months after birth. Males disperse farther than females. Females stay close to their home burrow with their range sometimes overlapping. Most young do not breed until the spring following their birth.
Parental Investment: female parental care
