346 Tamias striatusSlajchert et al. 1997; D. P. Snyder 1982; Thibault and Bovet
1999; White and Svendsen 1992; Wishner 1982; Wood 1993;
Yahner and Mahan 1997a, 1997b; Zollner and Crane 2003.
Tamias townsendii Bachman, 1839
Town s e n d ’s Chip munk
description: Townsend’s chipmunks are known for their
larger size, darker anterior pelage, and grayish posterior pel-
age. The dorsal stripes are dark, and the tail is dark with
white- or gray-tipped hairs. The ventral surface is white or
cream colored.
size: Female—HB 146.3 mm; T 115.9 mm; Mass 76.1 g.
Male—HB 141.8 mm; T 110.5 mm; Mass 70.3 g.
Sex not stated—HB 139.0 mm; T 110.9 mm; Mass 104.0 g.
distribution: This species occurs in southwestern Brit-
ish Columbia, including Vancouver Island (Canada), south
through western Washington and Oregon to the Rogue
River (USA).
geographic variation: Two subspecies are recognized.
T. t. townsendii—sout hwest corner of British Columbia (Can-
ada) southward along the coast of Washington and Ore-
gon to the Rogue River in southern Oregon (USA). The
range extends inland about 200 km in Washington and
100 km inland in Oregon. This subspecies is large, and
the upperparts vary from yellowish olive gray to rich
yellow brown. The dark dorsal stripes are black or
brownish black.
T. t. cooperi—southwestern British Columbia (Canada) south-
ward to the Rogue River in Oregon (USA), and inland
along the entire eastern edge of the range of T. t. town-
sendii for about 100 km. This form is grayer and lighter
colored. The dark dorsal stripes tend to be grayer rather
than browner.conservation: IUCN status—least concern. Population
trend—stable.habitat: T. townsendii is a n a rborea l chipmun k found in t he
dense underbrush of mesic closed-canopy forests. This spe-
cies is more common in upland stands; reproductive indi-
viduals, however, are more abundant in riparian forests,
while juveniles appear to prefer upland habitat. Densities
rise in forest clearcuts where the quantity of herbaceous
plants and shrubs increases after timbering has occurred,
but Townsend’s chipmunk can also rely on riparian buff ers
following clearcutting. This species often nests on talus
slopes. The abundance and size of downed woody debris
infl uences the movement patterns—and quite possibly the
survival—of Townsend’s chipmunks.natural history: In cold temperate regions of the eastern
Cascade Mountains (USA), this species hibernates for four to
fi ve months. There, breeding occurs in late April to early May.
Hibernation varies with climate, however, and Pacifi c coastal
animals are often active throughout the year. Gestation is 28
days, and the young emerge from the nest around early July,
but some adults may remain sexually active through the sum-
mer, and lactation may occur as late as early August. Mean
litter size is 3.8. The young appear to become mature adults
by 3 months old, although reproduction does not occur until
the following year. Details of this species’ development from
birth to weaning are summarized by D. A. Sutton. Although
Townsend’s chipmunks are diurnal and active throughout
the day, clear peaks of activity occur in midday. T. townsendii
regularly feeds on seeds, fruits, tubers, and some vegetation,
and it regularly larder-hoards hazelnuts, acorns, and conifer
seeds. This species is also a mycophagist, consuming both
epigeous (aboveground) and hypogeous (underground) fungi;
the latter may increase in diversity and standing crop size
with certain forest management practices (e.g., retention of
larger live, dead, and fallen trees) or stand age. The most com-
mon genera of hypogeous fungi consumed are Melanogaster
and Rhizopogon, as indicated by spores in the animal’s feces.
In the Pacifi c Northwest, T. townsendii, along with Glauco-