348 Tamias umbrinustwo white stripes on the face, a brown to cinnamon stripe
through the eyes, and a grayish head with white to cream
postauricular patches. The venter is white to cream. The tail
is grayish on the upper surface and orange to reddish below.
size: Female—HB 125.7 mm.
Male—HB 121.8 mm.
Both sexes—T 89–119 mm; Mass 51–74 g.
distribution: T. umbrinus is found from eastcentral Cali-
fornia through Nevada; extreme southwestern Montana
and eastern Idaho to northwestern Wyoming; Utah; south-
eastern Wyoming and northern Colorado; and northern
Arizona (USA).
geographic variation: Seven subspecies are recognized.
T. u. umbrinus—northern Utah and southwestern Wyoming
(USA). See description above.
T. u. adsitus—southwestern Utah and northern Arizona
(USA). The sides are darker and the rump is less brown.
T. u. fremonti—northwest Wyoming (USA) portion of the
range. The sides are yellow, and the postauricular patches
are grayish white.
T. u. inyoensis—eastern California, Nevada, and western
Utah (USA). This is a relatively dark form.
T. u. montanus—pri ma ri ly i n Colorado ( USA), w it h a d isjunc t
range. The sides are gray, and the feet a cinnamon buff
color.
T. u. nevadensis—endemic to the Sheep Mountains of south-
ern Nevada (USA). This subspecies has a relatively gray
dorsum.
T. u. sedulus—endemic to the Henry Mountains of south-
eastern Utah (USA). The dorsum is more reddish brown,
the sides are yellowish, and the ventral portion of the tail
is ochraceous orange.conservation: IUCN status—least concern. Population
trend—stable. T. u. nevadensis is considered a sensitive spe-
cies in Nevada (USA).habitat: Uinta chipmunks inhabit coniferous forests, par-
ticularly those dominated by pine (Pinus), fi r (Abies), and
spruce (Picea), often at the highest elevations when other
chipmunk species overlap with it in distribution.natural history: This species is diurnal. Uinta chip-
munks probably do not hibernate and can be active year-
round in favorable weather; individuals will remain in nests
during poor weather and may enter short bouts of torpor. T.
umbrinus begins breeding in the spring. Nests are located
under rocks, in underground burrows, and in tree cavities
or the old arboreal nests of other species. This species is
more arboreal than many chipmunks, and Uinta chipmunks
frequently climb shrubs and trees in search of food and to
nest. T. umbrinus is an herbivore, principally eating the
seeds and fruits of trees, but it also incorporates a diversity
of fungi into its diet and will eat insects, bird eggs, and other
animal matter. Like many chipmunks, seeds are the princi-
pal component of Uinta chipmunk diets; they are carried in
cheek pouches, placed in underground burrows, and cached
for overwinter use. The overwinter survival rate for Uinta
chipmunks is often extremely poor, with local extirpation
being common. Due to the modest size of this chipmunk, its
predators include a variety of raptors, mustelids, felids, and
canids. T. umbrinus often retreats to the protective cover of
shrubs or trees when under threat. Uinta chipmunks are ter-
ritorial, and they aggressively defend areas from all other
species of chipmunks. Tail movements are most often hori-
zontal when an animal is excited. This chipmunk possesses
a loud high-pitched alarm call and vocalizes frequently when
confi ned. Uinta chipmunks are not trapped or hunted; how-
ever, they are occasionally a nuisance near homes or in pic-
nic areas.general references: Bergstrom 1992; Bergstrom and
Hoff mann 1991; Levenson 1990.Tamias umbrinus. Photo courtesy Kelly McNulty, 2010.