The Desert Tortoise of North America

Analysis of the Desert Tortoise of North America

The desert tortoise is one of the four species of on land tortoises in North America. They are the longest living reptile of the southwestern United States region, living from eighty years up to one hundred years. They are well adapted to living in a highly variable and often harsh environment.

On April 2, 1990; the U.S. Fish and Wildlife Service listed the desert tortoise as a threatened species. Their populations have been decreasing for many years due to habitat loss and disturbance, collection for pets, raven predation of eggs and juveniles, and a respiratory disease mostly caused by captive tortoises being released into the wild. It is illegal to collect desert tortoises from the wild without a permit from both the federal government and the states of California, Nevada, Utah, and Arizona.

It is also illegal to buy or sell desert tortoises. The only legal way for an individual to acquire a desert tortoise is to adopt one from a State Game and Fish sanctioned organization or to receive a captive-born hatchling as a gift.

Appearance

Desert tortoises have a highly domed, distinctly ridged carapace ranging in length from 6 to 15 inches. Adults weigh in between 8 and 15 pounds. The carapace, which is the upper shell of a tortoise, is brown or horn colored. The plastron, the lower shell, is yellow-hued and without a hinge. Male tortoises have extended gular shields used in combat with other males during the breeding season. Both sexes have stout, elephant-like limbs which allows these reptiles access to an amazing range of microhabitats, from shallow desert washes to extremely steep mountainous slopes.

The desert tortoises scaly reptilian skin is tough and protects against water loss. Their sharp claws and strong legs provide the tools needed to dig deep burrows. One way to differentiate a male tortoise from a female is by size and tail length. The male should be both larger and have a longer tail than its female counterpart. Adult male tortoises also have a concave plastron used for mounting females during breeding season.

Range

The natural range of the desert tortoise encompasses both the Sonoran and Mohave deserts in Southwestern Utah, Southern Nevada, Southeastern California, and Western Arizona in the United States. They also occur in the Sinaloan deserts in Northern Mexico.

To survive the harsh environment of the hot, dry desert; desert tortoises dig burrows under rocks or at the base of bushes.