- San Joaquin antelope squirrel of California
- Harris' antelope squirrel of Arizona and Sonora, Mexico
- White-tailed antelope squirrel, from New Mexico and Arizona northward to Oregon
- Insular antelope squirrel, of Baja California
- Texas antelope squirrel, of southwestern Texas, New Mexico, and northern Mexico
The range of the Texas antelope squirrel lies mostly along the Rio Grande and Pecos rivers of southwestern Texas and New Mexico. It inhabits rocky desert regions, usually in proximity to mountain ranges. It is a buff or gray ground squirrel with a single white line along each side. The tail appears somewhat flat, and is often carried arched over the back.
The Texas antelope squirrel is one of the few animal species that remains active throughout even the hottest summer desert days, even when temperatures soar to well over 100 degrees Fahrenheit. They deal with the heat by occasionally finding a shady spot, where they will lie flat with limbs outstretched, allowing their excess body heat to dissipate through the belly to the cooler shaded ground.
Given the arid environment, the Texas antelope squirrel has a surprisingly varied diet. It feeds on the seeds of yucca, juniper, mesquite, salt grass, sotol, the ripe fruits of cactus such as prickly pear and cholla, and insects.
These little squirrels nest in burrows that they dig, usually in the shade of a clump of bushes or a boulder, or the side of a river bank. The nest inside the burrow is lined with rabbit fur, feathers, shredded bark, or dry grass.