Spotlight: Desert Tortoise (Gopherus agassizii), the State Reptile of Nevada and California Range: Northern Mexico as well as the Sonoran and Mojave Deserts of Arizona, California, Nevada, and Utah. Status: Critically Threatened Habitat: Deserts, sandy flats, and rocky foothills. Soil type is very important as they can spend as much as 95% of their lives in burrows. Their burrows offer escape from both excessively high and low temperatures, which helps to control body temperature and water loss. Desert tortoises' activity is strongly influenced by external temperature. They usually brumate (the cold-blooded equivalent of hibernation) during colder months (November through March).
Threats: Desert Tortoises are herbivores with an estimated lifespan of between 50-80 years, so undisturbed ecosystems are of great importance to their survival. Predators include ravens, foxes, badgers, coyotes, road runners, and fire ants. Juveniles, whose shells do not harden till roughly five years of age, are particularly susceptible to predation. Respiratory and shell diseases are also affecting wild populations.
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