Xerospermophilus spilosoma 369(México). The dorsum of this subspecies is dark and
yellowish.
X. s. ammophilus—extreme northern Chihuahua (México).
This is an extremely pale form found on the sand dunes
south of the city of Juárez.
X. s. annectens—southern Texas and the Rio Grande Valley
(USA). This subspecies exhibits no distinctive color-
ation, but it has a slightly longer skull that is narrower at
the base and broader at the interorbital region.
X. s. bavicorensis—endemic to the basin of the Laguna de
Babícora in westcentral Chihuahua (México). This is a
large subspecies that has an unusually blackish pelage.
X. s. cabrerai—San Luis Potosí and vicinity, in central
México. This is a largish form, with a darker dorsum.
X. s. canescens—southcentral New Mexico southeast through
Texas (USA) into Coahuila (México). This subspecies has
a reddish hue, with spots that are larger and more nu-
merous on the posterior dorsum; the apex of the tail is
dark.
X. s. cryptospilotus—Four Corners area of Arizona, Utah,
Colorado, and New Mexico (USA). This is a pale and
more reddish form, with distinct small spotting on the
dorsum.
X. s. marginatus—southeastern Colorado, southwestern
Kansas, New Mexico, western Texas, and the panhandle
of Oklahoma (USA). This subspecies has a reduced num-
ber of dorsal spots; the dorsum is pale and gray, tinged
with red.
X. s. obsoletus—southeastern Wyoming, northeastern Colo-
rado, western Nebraska, and northwestern Kansas (USA).
This typically drab form has less distinct and sometimes
obsolete spots on the dorsum.
X. s. oricolus—coastal Tamaulipas, in northeastern México.
This form is distinctly spotted, with near cinnamon buff
on the hind feet.
X. s. pallescens—central México. This subspecies is darker on
the posterior dorsum, with fi ner spots.
X. s. pratensis—northern Arizona (USA). This is a smallish
short-tailed form, with a darker dorsum and tip of the
tail.conservation: IUCN status—least concern. Population
trend—stable.habitat: Spotted ground squirrels are found in deep sandy
soils with sparse vegetation, including desert grasslands, des-
ert scrub, heavily grazed pastures, sand dunes, coastal plains,
and grassy urban parks, cemeteries, and schoolyards.natural history: X. spilosoma is diurnal. Spotted ground
squirrels hibernate in burrows for seven to eight months,
but they may stay active or only enter short bouts of torpor
during mild winters. Yearlings are the fi rst to emerge, fol-
lowed by older adult males and, fi nally, adult females (afterXerospermophilus spilosoma. Photo courtesy Randall D. Babb.