352 Urocitellus beldingifrom both oral and dorsal apocrine glands that are used for
the identifi cation of close kin and unfamiliar relatives. Such
odors vary in a linear fashion with heritability, and there-
fore permit the detection of distant relatives, although U.
beldingi only display nepotistic behavior toward close kin.
Littermate preferences are indirectly infl uenced by the pres-
ence (but not by the interaction) of the mother. Mortality
results from heavy snows, especially when they occur after
emergence. Predators of Belding’s ground squirrels include
a wide range of mammalian carnivores, rattlesnakes (Crota-
lus viridis), and even Clark’s Nutcrackers (Nucifraga columbi-
ana). Ectoparasites such as fl eas, ticks, mites, and lice are
common, but endoparasites (e.g., Entamoeba) are limited be-
cause of this species’ herbaceous diet. U. beldingi is sympat-
ric with U. columbianus. Belding’s ground squirrels can cause
signifi cant damage to agricultural crops; yield losses in al-
falfa fi elds, for example, can be as high as 45 percent.
general references: Anthony 1928; Bushberg and Hol-
mes 1985; Chappell et al. 1995; Dobson and Jones 1985; Dun-
can and Jenkins 1998; Holekamp 1986; W. G. Holmes 1984;
W. G. Holmes and Mateo 1998; S. H. Jenkins and Eshelman
1984; A. W. Linzey and Hammerson 2008c; Mateo 1996,
2002, 2003, 2006a, 2006b; Mateo and Holmes 1997, 1999; Ma-
teo and Johnston 2000; McCowan and Hooper 2002; Nunes,
Duniec, et al. 1999; Nunes, Ha, et al. 1998; Nunes and Hole-
kamp 1996; Nunes, Muecke, Anthony, et al. 1999; Nunes,
Muecke, and Holekamp 2002; Nunes, Muecke, Lancaster,
et al. 2004; Peacock and Jenkins 1988; Trombulak 1989; Verts
and Costain 1988; Whisson et al. 1999.
Urocitellus brunneus (A. H. Howell, 1928)
Idaho Ground Squirrel
description: The Ida ho g round squi rrel is recog nized by it s
small head and body; short tail; distinct eye ring; and brown-
ish dorsal pelage, with white spots. The nose, the legs, and
the ventral surface of the tail are yellow pink to orange. The
pinnae are larger and the pelage darker than those of both U.
townsendii and U. washingtoni. The spotting on the dorsal pel-
age in U. brunneus is more distinct, and the lateral line less
distinct, than those of U. townsendii. Compared with U. wash-
ingtoni, the dorsal spots are smaller and the lateral line less
distinct. U. brunneus is distinguished from other congeners
(U. armatus, U. beldingi, and U. elegans) by its smaller size.
size: Female—HB 173.6 mm; T 54.7 mm; Mass 116.8 g.
Male—HB 183.4 mm; T 55.1 mm.
Sex not stated—HB 179.0 mm; T 54.0 mm; Mass 205.0 g.
distribution: Endemic to westcentral Idaho (USA), U.
brunneus is found in only three isolated areas: north of the
Payette River to the Cuddy and Hitt mountains; between
the Seven Devils and Cuddy mountains; and east of the
West Mounta ins.geographic variation: Two subspecies are recognized.U. b. brunneus—northern portion of the species’ range, in
the Seven Devils Mountains and to the southeast, east of
the West Mountains (USA). The dorsal pelage is dark
gray with a reddish wash.
U. b. endemicus—southern terminus of the species’ range, in
Washington, Payette, and Gem counties in Idaho (USA).
This subspecies occurs at lower elevations than U. b.
brunneus. The dorsal pelage is grayer than that of U. b.
brunneus; the base of the tail and the legs are brown.conservation: IUCN status—endangered. Population
trend—decreasing. U. b. brunneus is considered highly threat-
ened, and in 2000 it was formally listed as threatened by the
U.S. Fish and Wildlife Service under the Endangered Spe-
cies Act.habitat: The Idaho ground squirrel is typically found in
meadows composed of forbs and grasses. In the northern
part of the species’ range, its preferred habitat is reported to
be open conifer stands with a dense herbaceous understory.
Loss of such habitat has resulted from logging and fi re sup-
pression, which both contribute to this species’ decline.