Squirrels of the World

Tamias o chrogenys 329

of burrows and nests, which vary widely, are reported from
boulder fi elds, fallen logs, and cacti (for T. o. meridionalis).
Like its congeners, T. obscurus feeds on seeds and fruits, es-
pecially acorns, which it frequently larder-hoards in bur-
rows. Predators are not reported for this species; parasites
include four species of Eimeria, one fl ea, and one mite. Sym-
patric populations of T. merriami and T. speciosus occur
within the range of T. obscurus. The breeding season appears
to be particularly long for this species; it begins as early as
January and continues to as late as early June. The southern-
most populations of this species (T. o. meridionalis) appear to
reproduce earliest and are reported to have young in the
nest by February. T. obscurus produces litters of three to four
individuals and, although speculation exists that two litters
may be produced, one is more likely.

general references: Best and Granai 1994b; A. W. Lin-
zey, Timm, et al. 2008c.

Tamias o chrogenys (Merriam, 1897)

Yellow-Cheeked Chipmunk,

Redwood Chipmunk

description: T. ochrogenys is distinguished from other
members of the townsendii complex (T. senex, T. siskiyou, and
T. townsendii) by its larger body size, dark dorsal pelage,
thinner tail, the structure of its genital bones, and its vocal-
izations. In addition, its body size is larger, its pelage is

darker, and its tail is shorter than those of T. sonomae and T.

merriami, which can be found in the southern part of the

range of T. ochrogenys.

size: Female—HB 152.5 mm; T 115.1 mm; Mass 94.1 g.

Male—HB 147.8 mm; T 109.0 mm; Mass 72.7 g.

Sex not stated—HB 148.7 mm; T 113.8 mm; Mass 94.1 g.

distribution: The yellow-cheeked chipmunk is found

along the coast of northern California, from the Van Duzen

River south to southern Sonoma County (USA).

geographic variation: None.

conservation: IUCN status—least concern. Population

trend—stable.

habitat: This species is found in the coastal redwoods (Se-

quoia sempervirens) of the northwestern coast of California

(USA). Its preferred habitat appears to be moist conifer for-

ests with thicker underbrush. This species is limited to for-

ests within 40 km of the coast, at elevations from sea level

to 1280 m.

natural history: A lt hough detailed studies on t he diet of

T. ochrogenys are not available, anecdotal reports suggest

that it feeds on a broad selection of seeds (from grasses and

Tamias ochrogenys. Photo courtesy Lisa D. Walker, http://www.sun

riseseaglass.com.