endemic to a single nation

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Eastern Oregon (except northeastern and southeastern corners), extreme northwestern Nevada, west side of Snake River in westcentral Idaho (Hoffman et al., in Wilson and Reeder 1993).

Length: 27 cm

Weight: 325 grams

• Terrestrial

Comments: Mainly in high desert (sagebrush, shadscale, greasewood, western juniper), grasslands, pastures (Rickart, in Wilson and Ruff 1999); also in river valley bottomland. Generally in well-drained soils, especially embankments. Often around desert springs and irrigated fields. Makes extensive burrow systems. Young are born in a nest chamber in an underground burrow.

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Comments: Main diet herbaceous vegetation (grasses, forbs, and exotic annuals), and seeds; may also eat some shrub parts and animal matter. Will often feed on crops. May climb bushes while foraging.

Comments: Emerges from dormancy in late winter or early spring (males before females) but returns to dormancy during May-July, when grasses dry out. May have separate period of activity in fall. Most active in the early morning.

Based on the related species S. MOLLIS (Rickart 1987, 1988), may be characterized as follows: Drought may suppress breeding. Gestation lasts 24 days. Litter size typically is 5-10; 1 litter per year. Males mature as yearlings or as 2-year-olds; females breed as yearlings.

United States

Rounded National Status Rank: N4 - Apparently Secure

Rounded Global Status Rank: G4 - Apparently Secure

Comments: Causes agricultural damage in some areas; has been subject of control programs.

Comments: Spermophilus canus and S. mollis formerly were included in S. townsendii. Baker et al. (2003) and Thorington and Hoffmann (in Wilson and Reeder 2005) recognized the three taxa as distinct species, noting their distinct cytotypes and lack of hybridization. Includes vigilis (Wilson and Reeder, 2005).