Urocitellus mollis

Piute Ground Squirrel

Family: Sciuridae · Class: Mammalia · Order: Rodentia

Conservation status: G5 S3

The Piute ground squirrel is a medium-sized rodent measuring 200-280 mm (7.9-11.0 inches) in total length, with a tail comprising approximately one-third of this length at 60-110 mm (2.4-4.3 inches). Adults typically weigh 150-400 grams (5.3-14.1 ounces). The dorsal pelage is grayish-brown to buff-colored with indistinct mottling, while the ventral surface is pale gray to whitish. The tail is moderately bushy with alternating dark and light bands, and the ears are relatively small and rounded. Distinguished from related ground squirrels by its larger size and less distinct dorsal spotting pattern. Historically, the Piute ground squirrel ranged throughout the Great Basin and adjacent areas of the western United States. In California, the species occurs primarily in the eastern Sierra Nevada region, including Mono and Inyo counties, extending into portions of the Modoc Plateau in northeastern California. The current California distribution represents the southwestern periphery of the species' broader range, which extends through Nevada, Utah, southeastern Oregon, and southwestern Idaho. Piute ground squirrels inhabit arid and semi-arid environments characterized by sagebrush scrub, pinyon-juniper woodland, and mountain mahogany communities. The species occurs at elevations ranging from 1,200 to 3,400 meters (3,900 to 11,200 feet), though most California populations are found between 1,800 and 2,800 meters (5,900 to 9,200 feet). Preferred habitats include open areas with scattered shrubs, rocky outcrops, and well-drained soils suitable for burrow construction. Burrow systems typically extend 1-3 meters underground with multiple entrances. The species exhibits a prolonged hibernation period, remaining inactive from September or October through March or April, depending on elevation and local climate conditions. Active periods coincide with peak vegetation growth from late spring through early fall. Piute ground squirrels are primarily granivorous, feeding on seeds of grasses, forbs, and shrubs, particularly sagebrush and bitterbrush. They also consume green vegetation, flowers, and occasionally insects. Breeding occurs shortly after emergence from hibernation, with females producing a single litter of 4-8 young after a gestation period of approximately 28 days. Juveniles emerge from burrows in mid to late summer. The Piute ground squirrel is not federally or state listed but carries a California state rank of S3, indicating the species is vulnerable within the state. The Global rank of G5 suggests the species is secure range-wide. Primary threats in California include habitat fragmentation from development, grazing impacts, and climate change effects on high-elevation habitats. Population trends in California are not well-documented, but the species' peripheral distribution in the state makes local populations potentially more vulnerable to environmental changes. Conservation efforts focus on habitat protection within existing protected areas and monitoring of population trends in key locations.

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, and more.