DESCRIPTION: A large (shell up to 380 mm or 15″ in length) land tortoise with a dome-shaped carapace (top part of shell) that is marked by distinct growth rings. Coloration can be horn, orange-brown, gray-brown, dark gray, or nearly black. The underside of the shell (plastron) is usually tan or yellow. The tail is short. The hind limbs are short, rounded, thick, and elephant-like. The forelimbs are flattened for digging, are longer than the hind limbs, and are armored with large, thick scales. The head is relatively small and rounded. In males the gular shields of the plastron extend out underneath the throat (see figure below).This tortoise has shorter gular shields and a more narrow shell-width than the similar looking Agassiz’s Desert Tortoise.

DISTRIBUTION: This tortoise occurs along the western border south of the Colorado River and across most of southwestern and south-central Arizona at elevations ranging from near sea level along the Colorado River to just over 5,000′.

HABITAT: Primarily an inhabitant of Arizona Upland Sonoran Desertscrub and Mohave Desertscrub but also enters Semidesert Grassland and Madrean Evergreen Woodland communities in some parts of the state. Across most of our state this tortoise inhabits rugged uplands such as rocky bajadas, hillsides, mountain slopes, and canyons. Populations in northwestern Arizona inhabit more moderate terrain such as gentle bajadas and low valleys.

BEHAVIOR: Primarily diurnal and crepuscular but occasionally active into the night. The Sonoran Desert Tortoise is entirely terrestrial. It shelters and hibernates in self constructed burrows that are often excavated under large rocks. It uses its strong, paddle-like forelimbs to dig. Also shelters in naturally occurring cavities under rocks or in the banks of washes. When threatened it pulls the body and head into the shell and covers the opening with its thick, armored forelimbs.

DIET: This herbivore feeds on grasses, herbs, cacti, tree shoots, and other plant material.

REPRODUCTION: This tortoise mates from June through early August and lays a single clutch of up to 12 eggs the following June or July. The eggs are usually buried inside the burrow.

PROTECTED throughout Arizona
It is against Arizona State law to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect this animal in any part of the state. It is also illegal to attempt to engage in any such conduct.

Brennan, T. C., & A. T. Holycross. 2006. A Field Guide to Amphibians and Reptiles in Arizona. Arizona Game and Fish Department. Phoenix, AZ

Brennan, T. C., & A. T. Holycross. 2005. A Field Guide to Amphibians and Reptiles of Maricopa County. Arizona Game and Fish Department. Phoenix, AZ

Murphy RW, Berry KH, Edwards T, Leviton AE, Lathrop A, Riedle JD (2011) The dazed and confused identity of Agassiz’s land tortoise, Gopherus agassizii (Testudines, Testudinidae) with the description of a new species, and its consequences for conservation. ZooKeys 113: 39–71. doi: 10.3897/zookeys.113.1353

Stebbins, R.C. 1951. Amphibians of Western North America. University of California Press, Berkeley, CA.

Stebbins, R.C. 2003. A Field Guide to Western Reptiles and Amphibians, Third Edition. Houghton Mifflin Company, Boston, MA.