Squirrels of the World

330 Tamias o chrogenys

shrubs); fruits, such as raspberries (Rubus); acorns (Quercus);
fungi (especially in the late winter and spring); and even
insects. No predators are reported for yellow-cheeked chip-
munks, and the few parasites defi nitively recorded from
this species include the botfl y (Cuterebra) and one louse
(Hoplopleura arboricola). Little information is available about
reproduction and development in this species. Males are
known to be reproductively active between March and
June. Four fetuses (43 mm) were reported from one female
in mid-March. Visual detection of this species is diffi cult be-
cause of the thick underbrush of its habitat, but T. ochrogenys
can be recognized by its distinctive low-frequency two-part
“ch ip” ca l l. Th i s “ch ip” ca l l, mos t si m i la r to t hat produced by
T. townsendii, is of a lower frequency and has a distinctive
rhythm compared with that of other species in the townsen-
dii species-group. Hybridization between T. ochrogenys and
T. senex is hypothesized, based on the intermediate “chip”
vocalizations in Humboldt County, California (USA), south
of the Eel River.

general references: Gannon et al 1993; A. W. Linzey
and Hammerson 2008h.

Tamias p almeri (Merriam, 1897)

Palmer’s Chipmunk

description: This is a relatively small chipmunk, but it is
slightly larger than its only sympatric congener, T. panamin-
tinus. The overall pelage is dark to brown. The shoulders are
grayer, the body is browner, and the ventral surface is paler
than those characteristics of T. panamintinus.

size: Female—HB 126.1 mm; T 80.3 mm; Mass 55.2 g.

Male—HB 126.6 mm; T 98.0 mm; Mass 52.4 g.

Sex not stated—HB 125.5 mm, T 94.0 mm, Mass 59.7 g.

distribution: Tamia s p almer i’s entire range is restricted to

the Spring Mountains of Clark County in southern Nevada

(USA), where it is surrounded and isolated by desert.

geographic variation: None.

conservation: IUCN status—endangered. Population

trend—declining.

habitat: Palmer’s chipmunk is found at elevations from

2100 m to timberline (3600 m), but population densities are

highest between 2400 and 2550 m. This species is frequently

associated with rock crevices, rock outcrops, caves, and

Tamias palmeri. Photo courtesy Chris Lowrey.

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