The desert tortoise, Gopherus agassizii, is found in southwest Utah, southern Nevada, southeastern California, and western Arizona. Due to genetic, morphometric, and behavioral differences, the desert tortoise in Utah, commonly referred to the Mojave desert tortoise, is a different species than Sonoran desert tortoise (Gopherus morafkai), found south and east of the Colorado River. The Mojave desert tortoise is federally protected under the Endangered Species Act as a threatened species.
Desert tortoise populations are vulnerable to habitat loss or degradation because of their life history. They are long lived vertebrates, with life span estimates of 50 to 80 years, and have delayed sexual maturity, low reproductive rates, and high juvenile mortality. To regulate body temperature and reduce water loss, they spend a majority of time in shelters such as soil burrows, caves, rock shelters, and pallets. Within its range, the desert tortoise can be found in grasslands, canyon bottoms, and rocky hillsides. Females nest under a large shrub or at the mouth of a burrow, and lay one to three clutches of up to ten eggs from May to July; eggs hatch in late summer or fall.
The desert tortoise is an herbivore and its diet consists of perennial grasses, annual wildflowers, shrubs, and cacti including the pads, fruit and flower.