Family: Heteromyidae, Pocket Mice and Kangaroo Rats view all from this family
Description Soft-furred. Grayish yellow or buff above, interspersed with black hairs that vary from paler to darker with color of soil; underparts buff, brownish, or white. Tail uniformly pale brownish. 2 small white patches at base of ears. L 4 1/4-6" (110-151 mm); T 2 1/8-3 3/8" (53-86 mm); HF 5/8- 3/4" (15-20 mm); Wt 1/4 oz (7-9 g).
Endangered Status The Pacific Pocket Mouse, a subspecies of the Little Pocket Mouse, is on the U.S. Endangered Species List. It is classified as endangered in California. This coastal-dweller plummeted in number as residential development overtook its habitat. For about 20 years it was assumed to be extinct, but a single population of fewer than 40 mice was discovered in 1993. These remaining mice are preyed upon by feral and pet cats. The subspecies only hope for survival is the removal of cats from its vicinity and the preservation of its habitat or its relocation to a new habitat.
Similar Species San Joaquin Pocket Mouse occurs only in San Joaquin Valley, where this species does not occur. White-eared, Long-tailed, and Great Basin pocket mice are larger, with longer hindfeet. Arizona Pocket Mouse is generally larger. Silky Pocket Mouse is generally smaller.
Breeding Apparently reproductively active from spring through fall. 1 or 2 litters per year of 1-6 (average 4) young; gestation 22-23 days.
Habitat Gravelly soils in desert areas, often in rolling terrain or in areas with ravines or rock outcroppings. Associated plants are rabbitbrush, tumble mustard (Sisymbrium altissimum), blackbrush, sand sagebrush (Artemisia filifolia), Mormon tea, and yucca.
Range Southeastern Oregon, Nevada, w and s Utah, s California, and small isolated areas in n, sc, and sw Arizona.
Discussion This seasonally active pocket mouse may hibernate for long periods under adverse conditions; in California, it is inactive from October to January. The Little Pocket Mouse can survive in the wild for three to five years, a considerable time for such a small animal. In Nevada, the Kit Fox is an important predator, but presumably this mouse is eaten by all common predators where it occurs.
