Behavior: The desert tortoise is most active during the day (diurnal) or the morning and evening (crepuscular), depending on the temperature. This tortoise spends most of its life underground. It burrows under the sand to protect itself from extreme desert temperatures, which range from 140°F (60°C) down to well below freezing. Adults can survive for about a year without water. They produce a variety of sounds, including hisses and grunts. When in danger, tortoises can withdraw their head, legs, and tail into the shell.

Anatomy: The desert tortoise has a hard upper shell (the carapace) which is about 9 to 15 inches (23-38 cm) long. The flattened fore limbs are armored, muscular and used for burrowing. The rear limbs are column-like. They have a gular horn that extends from the front of the plastron (lower shell). When males fight other males, they use the gular horn to overturn an opponent. The tail is very short.

Diet: The desert tortoise is an herbivore (plant eater). It eats grasses, herbs, and a wide variety of desert plants.

Reproduction: The female lays 1 to 2 hard-shelled white eggs in each clutch. The eggs are laid in a shallow pit that she digs with her hind legs. She covers the eggs with sand, then abandons them. The temperature determines whether the babies will be male or female. Cool temperatures (79-87°F) result in male hatchlings; warm temperatures (88-91°F) result in female hatchlings.