Ammospermophilus nelsoni

This small brown squirrel has a white lateral stripe on each side. The dorsum is buffy, sometimes yellowish. Total length: 218-240 mm (Jameson and Peeters 2004).

Smaller than the California ground squirrel (Spermophilus beecheyi), which is an abundant species throughout the San Joaquin Valley. The latter lacks the distinctive white stripe on its sides. Antelope ground squirrels are often mistaken for chipmunks (Neotamias spp.), but the squirrels lack the black and white stripes on their faces and backs.

Habitat consists of dry flat or rolling terrain, with slopes less than 10-14 degrees, on alluvial and loamy soils, soils with sandy or gravelly texture, or fine-grained soils that are nearly brick-hard when dry. The species inhabits grassy, sparsely shrubby ground (shrubs include saltbush, ephedra, bladder pod, goldenbush, snakeweed, etc.); it also occurs in areas lacking shrubs where giant kangaroo rats are present. Habitats in order of decreasing favorability: (1) xerophytic stage of alkali desert scrub with shrubs sparsely distributed and with friable soils, at elevations greater than 4,000 feet, (2) annual grassland with less than 6 inches annual precipitation, friable soils, and abundance of Dipodomys ingens, (3) halophytic stage of alkali desert scrub with shrubs sparsely distributed and with friable soils, at elevations above 2,200 feet, and (4) annual grassland with 7-9 inches annual precipitation and abundance of Dipodomys heermanni. Habitats that are avoided included valley floor areas of alkaline soils, iodine bush, and spring saltbush, probably due to high water tables (Biosystems Analysis 1989). See also Best et al. (1990) for habitat synopsis. These squirrels seldom dig their own burrows; most often they use burrows made by other small mammals. Preferred burrow locations are under shrubs, in the banks of arroyos at the base of alluvial fans, and along roadcuts, pipelines, and drilling platforms (Biosystems Analysis 1989).

Half of remaining habitat supports fewer than 1 animal/ha, 15% of the remaining habitat supports 3-10 animals/ha (generally 4 or fewer per ha, California Department of Fish and Game 1990). SPERMOPHILUS BEECHEYI reportedly may restrict range of A. NELSONI (see Best et al. 1990). Among several predators, badger is most important. Lives in small groups.

Breeding season coincides with availability of green vegetation. Young are born in March, first seen above ground about the first week of April, at which time they gather food. Gestation lasts 26 days. One breeding season per year. Litter size is 6-12 (average 9). May live 5+ years, though usual life span is less than 1 year.