344 Tamias striatusT. s. quebecensis—Québec (Canada). This form is similar to T.
s. griseus, but T. s. quebecensis is smaller and darker; the
gray dorsal areas lack the buff y tones of T. s. griseus. The
white dorsal stripes do not extend to the base of the tail.
T. s. rufescens—Geauga County, Ohio (USA). This form has a
relatively short tail and a brilliant red coloration. The
rump is reddish tawny, the fl anks and the thighs are
bright ochraceous buff , and the feet are apricot buff.
T. s. venustus—extreme southwestern limits of the species’
range. The dorsal stripes are shorter, and the colors are
brighter and more intense than in T. s. striatus.
conservation: IUCN status—least concern. Population
trend—stable.
habitat: T. striatus occupies a variety of specifi c habitat
types, but it is generally associated with deciduous forests in
eastern North America. Its presence and abundance are typi-
cally determined by the availability of potential burrows,
tree stumps and downed woody debris, and mast-producing
trees. Downed woody debris appears to be especially impor-
tant for movement in areas of more open canopy, presum-
ably because of predation risks. Although this species is
strongly dependent on oaks, especially white oaks (Quercus
alba), population densities and habitat selection in some for-
ests may rely even more on the abundance of red maples
(Acer rubrum). Densities of T. striatus in one study showed
little variation in even-aged stands of northern hardwoods
that varied from sapling age to mature forests. Although
eastern chipmunks are sometimes more abundant in mature
forests than in fragmented stands, this species appears to be
relatively resilient to forest fragmentation. For example, it
readily moves across open clearcuts of approximately 250 m,
and the microhabitat surrounding its burrows does not diff er
in fragmented versus continuous forest. These chipmunks
do, however, show more vigilance in forested corridors of
fragmented landscapes than in continuous forests. Such in-
creased vigilance in more open areas may reduce the time for
maintenance activities (e.g., foraging).
natural history: The eastern chipmunk is largely graniv-
orous, feeding on seeds (such as those of conifers and maples),
fruits, and nuts, especially acorns (Quercus). This species also
frequently includes animal material in its diet, and it is con-
sidered a major predator of the young of ground-nesting
birds, especially in years when acorns or other mast is low.
Additional animals reported in this species’ diet include ar-
thropods, amphibians, snakes, and small mammals. Both epi-
geous (aboveground) and hypogeous (underground) fungi
are also consumed when available. T. striatus can be consid-
ered a central-place forager, collecting large quantities of
seeds and then transporting them to the nest. For example,
we observed more than 122 maple samaras in the cheek
pouches of a single roadkilled chipmunk. More profi table
food items may be carried farther than those of lower use-
fulness. Although the eastern chipmunk is classifi ed as a
larder-hoarder, it will frequently cache food in both scatter-
hoards and the larder(s) within its burrow. Underground
larders are often fi lled with numerous acorns (sometimes
upward of a hundred). Its scatter-hoarding behavior may
contribute to seed dispersal under some circumstances, but
not to the extent that is attributable to the eastern gray
squirrel (Sciurus carolinensis). Captive individuals in ambient
conditions are estimated to consume a mean of 32.7–35.7 kcal
of energy/day. Body temperature is typically maintained be-
tween 36°C and 40°C, depending on the ambient tempera-
ture. Heat loss is diffi cult when the ambient temperature is
above 36°C. The eastern chipmunk periodically reduces its
body temperature and metabolism during the winter period
to overcome cold temperatures and food shortages. These
torpor bouts usually last one to fi ve days. In contrast with
many other ground-dwelling sciurids, energy reserves for T.
striatus are stored primarily in the form of a larder rather
than as body fat. Experimental studies show that an in-
crease in the quality of the larder-hoard—especially the con-
centration of polyunsaturated fatty acids—reduces the depthTamias striatus. Photo courtesy Doris Potter / Focus on Nature
Tour s, In c.