Round-tailed ground squirrel (Spermophilus tereticaudus). A ground-dwelling squirrel that inhabits arid regions of the southwestern United States and northern Mexico, especially desert areas with soil suitable for digging burrows. Total body length about 20.4–27.8 cm, tail length 6–11.2 cm, body weight 110–170 g; the tail is not bushy and is rounded. Mainly feeds on green leaves and stems of plants, and also consumes seeds and insects. Active at dawn and dusk and will climb trees; may enter a shallow hibernation-like state called torpor, with males becoming active first and females subsequently entering the breeding season. Pregnancy lasts 25–35 days, and about six young are born at a time. Distribution and population are stable, so conservation status is Least Concern.