Family: Heteromyidae, Pocket Mice and Kangaroo Rats view all from this family

Description A large pocket mouse. Brownish gray, with distinct white spines or bristles on rump, and brownish line on side. Underparts yellowish white. Tail brownish above, whitish below, with prominent tuft. Hindfoot large. Large ears; long black or buffy hairs at front base of ear are nearly as long as ear. L 7 1/2–9 1/4" (190–235 mm); T 4–5 5/8" (103–143 mm); HF 7/8–1 1/8" (24–29 mm); E 3/8"– 1/2" (9–14 mm); Wt average 3/4 oz (23 g).

Similar Species San Diego Pocket Mouse has smaller ears and is usually found at lower desert elevations. Spiny Pocket Mouse is grayish or yellowish buff, with side line faint or absent. Desert and Bailey’s pocket mice lack spines or bristles on rump.

Breeding 1 litter per year, of 2–5 young, born March–June; sometimes a second litter. Gestation 25 days.

Habitat Coastal sage scrub communities on chaparral slopes.

Range Southwestern California.

Discussion Along the coast of southern California, this is the most common pocket mouse. It enters a state of torpor in response to low temperatures and reduced food supplies.