California Desert Tortoise
Scientific Name: Gopherus agassizii
Desert tortoises can travel as fast as 20 feet per minute for a short time, and cover as much as a mile of terrain in a day.
The desert tortoise is a shy, land-dwelling reptile, native to the Mojave and Sonoran deserts. They can live up to one hundred years.
STATUS: This animal is classified as Vulnerable by the International Union for Conservation of Nature (IUCN). Except for relying on their hard shells, or crawling into the burrows they have dug, they are defenseless. Newly hatched tortoises are especially at risk. Their natural predators are bobcats, foxes, badgers, and coyotes. But humans are their biggest enemies, whether capturing them (illegally) for the pet trade, running over them on the highway or with off-road vehicles, or even shooting them. Even humans trying to do the “right thing” by returning pets to the wild can cause serious harm by introducing diseases acquired in captivity to the wild population.
HABITAT: Sandy, gravelly areas in the deserts of the Southwestern United States. Shade from creosote, thorn scrub, and cactus vegetation is essential. They dig shallow burrows that can be as long as 30 feet, occupied by one or more individuals. Their uses range from temporary protection to long term occupation during periods of estivation and hibernation. They live in a communal den from November to March, in hibernation.
DIET: This herbivorous reptile eats available desert plants such as cacti and grasses. They rarely need to drink water, getting almost all of their water from the food they eat.
PHYSICAL CHARACTERISTICS: The most obvious feature is a hard, thick shell, which provides excellent camouflage. Their upper shell, or carapace, is moderately domed. The under shell, or plastron, has a “joust” (protrusion), which affords extra protection when they retreat into their shell. The protrusion is larger in males, and is often used to try to turn over a competing male if both are fighting over the same female. Their legs are short and elephant-like, perfect for walking on sand, with thick claws on each limb for digging in compacted soil.
The All-Important Tortoise
Desert tortoises actually help the survival of their major predators: mountain lions, bobcats, and coyotes. The holes they dig to reach cooler soil fill with water during infrequent desert rains, and water remains in these depressions far longer than it does on the flat desert floor. For much desert wildlife, these “watering holes” are the primary source of water between rainfalls. The fewer desert tortoises exist, the fewer water resources are available to other animals.