Squirrels of the World

Tamias canipes 319

habitat: T. bulleri occupies an extremely small range at the
juncture of three western states in México, in the Sierra
Madre Occidental biotic province. The region is character-
ized by rolling mountainsides, with sharply cut canyons, at
elevations of 2100–2400 m. At higher altitudes the vegetation
consists mostly of pine (Pinus), a few other species of coni-
fer, oak (Quercus), and quaking aspen (Populus tremuloides). At
lower elevations the habitat is typical of the scrub oak veg-
etation of the upper Sonoran zone, such as manzanita (Arc-
tostaphylos pungens), mountain mahogany (Cercocarpus), and
Ceanothus. T. bulleri is replaced by T. durangae on the western
slopes of the Sierra Madre (between Río Nazas and Río
Mezquital) and by T. dorsalis on the eastern slopes (north of
Río Nazas). T. bulleri prefers more heavily wooded forests,
whereas T. dorsalis is found in more open xeric habitats.

natural history: T. bulleri has been observed feeding on
the catkins of oak (Quercus), juniper seeds (Juniperus), and
the shoots of pine stems (Pinus), but no other information is
available on its diet. Predators are not known, and only one
fl ea (possibly Monopsyllus polumus) and one unidentifi ed
nematode have been reported from T. bulleri. The Buller’s
chipmunk appears to prefer forests with a signifi cant com-
ponent of rocks or downed woody debris. In Jalisco it ap-
pears to be sympatric with Otospermophilus variegatus and
Sciurus nayaritensis. T. bulleri is reported to nest in tree cavi-
ties and ground dens. The little that is known about its re-
production includes reports of two females with two and
three embryos each (on 18 July and 26 June, respectively),
lactating females (between 27 June and 20 July), and a sub-

adult on 13 May. Although one study reports sexual dimor-

phism in this species, another argues against it. In addition

to the characteristic vocalizations of Tamia s (“chucks,”

“chips,” and trills), this species produces a sound unique to

the genus.

general references: Álvarez-Castañeda, Castro-Arellano,

Lacher, et al. 2008c; Bartig et al. 1993; Escalante, Espinosa, et

al. 2003; Escalante, Rodríguez, et al. 2005.

Tamias canipes (V. Bailey, 1902)

Gray-Footed Chipmunk

description: This species is recognized by the gray color-

ation of the dorsal surface of its hind feet. T. canipes is small,

but it is larger than T. minimus.

size: Female—HB 131.6 mm; T 107.8 mm.

Male—HB 128.7 mm; T 98.4 mm.

Sex not stated—HB 128.9 mm; T 100.0 mm; Mass 70.0 g.

distribution: The gray-footed chipmunk is found in the

Capitan, Jicarilla, Gallinas, and Sacramento mountains of

southeastern New Mexico, as well as in Texas, where it is

found only in the Sierra Diablo and the Guadalupe Moun-

tains of western Texas (USA).

geographic variation: Two subspecies are recognized.

T. c. canipes—occupies most of the species’ range. It is not

dimorphic.

T. c. sacramentoensis—only in the Sacramento Mountains of

New Mexico (USA). It is dimorphic; males are smaller

than females.

Tamias bulleri. Photo courtesy Celia López-González, Instituto

Politécnico Nacional, México.