View Full Version : New Week 3 - Round-Tailed Ground Squirrel

November 17th, 2008, 12:15 PM
Round-tailed Ground Squirrel Spermophilus tereticaudus

Family: Sciuridae, Squirrels Description Various shades of cinnamon, with drab grayish cast above, slightly paler below. No stripes or mottling. Tail round, long, slender, not bushy; cinnamon or drab below. L 8–11" (204–278 mm); T 2 3/8"–4 3/8" (60–112 mm); HF 1 1/4–1 5/8" (32–40 mm); Wt 5–6 1/2 oz (142–184 g).

Breeding Mates late March–April; gestation is about 27 days. Litter size, ranging from 1 to 12 young, varies with abundance of rainfall and vegetation. One dry year brought average litters of 3.3 young, while a wet year saw an average of 9. Newborn weighs about 1/8 oz (3.7 g).

Habitat Flat, sandy desert areas; creosote scrub.

Range Southeastern California, Southern Nevada, and Southwest Arizona.

Discussion The Round-tailed Ground Squirrel is most active during mornings and evenings, avoiding the most intense heat by retiring to its burrow at midday or seeking shade under a plant. It will climb into bushes not only to obtain leaves, but also to get out of the sun and off the hot sand. This species hibernates from late September or early October to early January, though in some areas it remains active all year. Seeds, other plant parts, and insects are this animal’s chief foods, with green vegetation constituting about 80 percent, seeds 15 percent, and insects 5 percent of its diet in spring. In summer, its food is almost 100 percent green vegetation, while in fall greens drop to 75 percent of the total, with seeds making up the other 25 percent. It will sometimes eat cultivated crops, if easily available. The Round-tailed Ground Squirrel digs its own burrows or uses old burrows of other species; entrances, usually at the base of a bush, are not revealed by mounds, as the dirt is scattered. Young appear aboveground the first week in May and are weaned mid-May through June, at about five weeks. The males disperse, but the females tend to remain in their natal areas. Hawks, eagles, Coyotes, foxes, American Badgers, and Bobcats prey on this squirrel.