Desert tortoise

Gopherus agassiziigopherus morafkai

The desert tortoises are two species of tortoise native to the Mojave and Sonoran Deserts of the southwestern United States and northwestern Mexico and the Sinaloan thornscrub of northwestern Mexico. ''G. agassizii'' is distributed in western Arizona, southeastern California, southern Nevada, and southwestern Utah. The specific name ''agassizii'' is in honor of Swiss-American zoologist Jean Louis Rodolphe Agassiz. Recently, on the basis of DNA, geographic, and behavioral differences between desert tortoises east and west of the Colorado River, it was decided that two species of desert tortoises exist: Agassiz's desert tortoise and Morafka's desert tortoise . ''G. morafkai'' occurs east of the Colorado River in Arizona, as well as in the states of Sonora and Sinaloa, Mexico. This species may be a composite of two species.

The new species name is in honor of the late Professor David Joseph Morafka of California State University, Dominguez Hills, in recognition of his many contributions to the study and conservation of ''Gopherus''.

The desert tortoise lives about 50 to 80 years; it grows slowly and generally has a low reproductive rate. It spends most of its time in burrows, rock shelters, and pallets to regulate body temperature and reduce water loss. It is most active after seasonal rains and is inactive during most of the year. This inactivity helps reduce water loss during hot periods, whereas winter hibernation facilitates survival during freezing temperatures and low food availability. Desert tortoises can tolerate water, salt, and energy imbalances on a daily basis, which increases their lifespans.