258 Callospermophilus madrensissize: Female—HB 168.0 mm; T 65.0 mm; Mass 152.0 g.
Male—HB 169.0 mm; T 64.0 mm; Mass 151.0 g.
Sex not stated—HB 175.0 mm; T 58.0 mm.
distribution: C. madrensis is found in northwestern
México. Historically, specimens were only reported from
southwestern Chihuahua (México), but this species has now
been documented in the state of Durango as well.
geographic variation: None.
conservation: IUCN status—near threatened. Population
trend—no information.
habitat: C. madrensis occurs in conifer forests of the Sierra
Madre Occidental biotic province above the pinyon pine
belt, typically at elevations between 3000 and 3750 m. This
species is associated exclusively with conifer forests of fi r
(Pseudotsuga), pine (Pinus), juniper (Juniperus), and some-
times quaking aspen (Populus tremuloides).
natural history: Between two and fi ve embryos have
been reported from four individuals, and lactation has been
observed in July. Nothing else is known about the popula-
tion biology, ecology, behavior, or genetics of this ground
squirrel. One species of sucking lice (Enderleinellus suturalis)
is reported from C. madrensis. The Sierra Madre ground
squirrel is signifi cantly threatened by habitat loss due to
deforestation. general references: Álvarez-Castañeda, Castro- Arellano,
Lacher, et al. 2008b; Arita and Ceballos 1997; Best and
Thomas 1991; Durden and Musser 1994a, 1994b; R. G. Harri-
son et al. 2003; Herron, Castoe, et al. 2004; Sánchez- Cordero
et. al. 2005; Servin, Alonso-Perez, et al. 2003; Ser vin, Sánchez-
Cordero, et al. 1996.
Callospermophilus saturatus
(Rhoads, 1895)
Cascade Golden-Mantled Ground
Squirreldescription: Cascade golden-mantled ground squirrels
are grizzled gray brown to charcoal on the dorsum, suff used
with buff to ochre. The top and sides of the head and the
shoulders have a variable and sometimes indistinct russet
mantle. The most distinguishing characteristic for this spe-
cies is the single white dorsal stripe that extends from the
shoulder to the hip on each side; a black line off sets eachCallospermophilus madrensis. Photo courtesy Juan Cruzado.