Family: Sciuridae, Squirrels view all from this family
Description Grayish, with stripes on body indistinct or absent; often more distinct on sides of head. Bushy tail rust-red below. L 7 5/8–10 7/8" (195–277 mm); T 3 3/8–5 1/2" (85–140 mm); HF 1 1/4–1 1/2" (32–39 mm); Wt 2–3 oz (57–85 g).
Similar Species Least, Uinta, and Gray-collared chipmunks have distinct striping on back. The two other chipmunks with indistinct striping, Merriam’s and California chipmunks, occur farther west in California.
Breeding Mates April–May, producing 4–8 young; some individuals have more than 1 litter.
Habitat Rocky areas and cliffs, especially pinyon-juniper zones, but also in ponderosa pine, oak, and maple.
Range Eastern Nevada, Utah, and extreme nw Colorado south to Arizona and w New Mexico.
Discussion Like most of its kin, the Cliff Chipmunk hibernates in winter (except apparently in Arizona), but it may emerge during warm spells. This species forms feeding aggregations of up to 10 individuals, mostly females. These groups move slowly through a feeding area, each member separated from the next by 10 to 30 feet (3–10 m), collecting many kinds of nuts, seeds, fruits, and berries. Storable items are taken directly to the main den or to a cache; many of the cached items are later taken to the main den for winter use. Dens are usually in cliffs or rock piles, but may be in underground burrows or in trees. This vociferous species gives a sharp bark about 160 times per minute, each accompanied by a tail twitch. Its other common calls are a chirping whsst or psst given when the animal is excited, and a high-pitched mixture of sounds employed when the animal is surprised or threatened. As with Merriam’s Chipmunk and others of brushy areas where small twigs cast indistinct shadows, the Cliff Chipmunk’s indistinct striping serves as protective coloration. This species may occur in close proximity with other chipmunk species, each occupying a slightly different ecological niche.
