Family: Muridae, Mice and Rats view all from this family

Description Upper parts yellowish orange to cinnamon-buff; white below. Dark populations occur on lava areas of Southwest. Tail sparsely haired, indistinctly bicolored, longer than head and body. Ears relatively large, nearly hairless. L 6 1/4 –8 5/8" (160–218 mm); T 3 1/4 –5" (84–128 mm); HF 3/4– 7/8" (18–22 mm); E 1/2 –3/4" (13–20 mm); Wt 5/8 –1 3/8 oz (18–40 g).

Similar Species Canyon Mouse’s tail is somewhat tufted at tip; when the two species occur together, the Canyon Mouse occupies the rockier areas. Brush Mouse has long hairs toward tip of tail. White-ankled Mouse’s tail is more clearly bicolored. Piñon Mouse has larger ears. California Mouse has well-furred tail. Merriam’s Mouse is usually in shrubby lowland areas with deep soil.

Breeding Reproductively active throughout year, but less so during hottest periods; average litter 2 or 3 young; gestation 21 days. Newborn weighs 1/16 oz (2.1–2.9 g).

Habitat Deserts, especially rocky outcroppings with cactus or yucca stands.

Range Southern California, s Nevada, extreme sw Utah, Arizona, s New Mexico, and sw Texas.

Discussion Well adapted to desert living, the Cactus Mouse tolerates higher temperatures and needs less water than most other North American deer mice. Often climbing to forage, this species is known to eat the fruit and flowers of shrubs such as mesquite and hackberry, some green vegetation, and insects. Seeds of desert annuals constitute the major portion of its diet. The Cactus Mouse hoards food and can become torpid during the day and during food shortages. It may nest in clumps of cactus, among rocks, or in the abandoned burrows of other small mammals. This species produces tooth-chattering sounds, squeals, and single chits when it is in aggressive situations, injured, or defending the nest.