The Living Desert
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Desert Tortoise

Gopherus agassizii

Family:

Testudinidae, the tortoise family.

Conservation Status:

IUCN Vulnerable. The population in the Mojave Desert of California, Nevada and Utah is listed as Threatened on the U.S. Endangered Species list.

Distribution:

Mojave and Sonoran deserts.

Habitat:

Dry desert washes, flats or hillsides.

Factoid:

Their large bladders serve to store water. They may expel this precious water as a means of defense when frightened.

Desert tortoises have high-domed carapaces, round, stumpy hind legs and flattened, front legs covered with large rigid scales to protect them from moisture loss. A forward extension of the plastron – the gular shield – is longer in males than in females and the plastron is concave on males and flat on females.

During the summer tortoises escape the midday heat in a shallow, crescent-shaped burrow while winter hibernation/estivation burrows can be 30 ft. long and used communally.
Tortoises are herbivores feeding on grasses, wildflowers and succulent plants. They will drink water when available, but much of their moisture comes from their diet.

Coyotes, bobcats, badgers, roadrunners and ravens prey on soft-shelled hatchlings. By the age of 4 or 5, their shells have hardened and they are less vulnerable.

They reach maturity at 15-20 years. Males competing for females may threaten each other with head-bobbing and ram each other, trying to flip each other. An upside-down tortoise may die unless able to right itself. Males also bob their heads at females, often biting their legs before mating. Females dig burrows where 1-14 leathery eggs are deposited which hatch about 3 months later. Hatchlings emerge in late summer and are on their own.

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