(Gopherus agassizii and Gopherus morafkai)
Desert Tortoise are native to the Mojave and Sonoran Deserts of the southwestern United States and northwestern Mexico and the Sinaloan thornscrub of northwestern Mexico. The desert tortoises live about 50 to 80 years; they grow slowly and generally have low reproductive rates. They spend most of their time in burrows, rock shelters, and pallets to regulate body temperature and reduce water loss. They are most active after seasonal rains and are inactive during most of the year. This inactivity helps reduce water loss during hot periods, whereas winter hibernation facilitates survival during freezing temperatures and low food availability. Desert tortoises can tolerate water, salt, and energy imbalances on a daily basis, which increases their lifespans. Desert tortoises can live in areas with ground temperatures exceeding 140 °F (60 °C) because of their ability to dig underground burrows and escape the heat. At least 95% of their lives are spent in burrows. There, they are also protected from freezing winter weather while dormant, from November through February or March. Within their burrows, these tortoises create a subterranean environment that can be beneficial to other reptiles, mammals, birds, and invertebrates.