|Desert tortoise (Gopherus agassizii) 15 inches long
Desert tortoises may reach up to 15" in length. They can be seen most readily in springtime when temperatures are still moderate and green vegetation is young and tender. Though they will drink from pools and puddles, most of the water they get is from the plants they eat and from synthesis in their own bodies. The desert tortoise can drink up to 40 percent of its weight in water and store it for use in the drier season. Their shells are pretty much waterproof, and they seek shelter both from extreme heat and from cold in shallow holes and large, underground communal burrows, depending on local climate.
Although they can live up to 100 years, desert tortoises are endangered because of habitat loss, road injuries, disease, and over-collection. No one should attempt to capture specimens; it is illegal. You should not handle a desert tortoise in any way. If you find one in a developed area call a wildlife agency or the local game and fish office for instructions.
Below is a photo of the Sonoran desert tortoise, a regional variant of the species.
Sonoran desert tortoise
Drawing of the desert tortoise by Bob Savannah, USFWS
The line drawing above is from the U.S. Fish and Wildlife Service. It is by nature artist Bob Savannah. This and many other nature drawings are available at http://www.fws.gov/pictures/lineart/bobsavannah/
These images are in the public domain; this means that they are not copyrighted, and you do not need to obtain permission to use them. The USFWS requests that you include a credit citation such as Credit: U. S. Fish and Wildlife Service or U. S. Fish and Wildlife Service / Bob Savannah