The Low-stress Life of the Desert Tortoise

[OPPOSITE PAGE] This lucky desert tortoise (Gopherus agassizii) beat the odds. Only a few hatchlings from every hundred eggs survive to adulthood, but adults can live up to 100 years.

[ABOVE] The rocky, sloping terrain of the Sonoran Desert still supplies shaded areas, occasional rainwater and a gourmet diet of herbs, grasses, select shrubs and cactus for this young adult.

within a few miles of where they hatched. Mating, while appearing logistically cumbersome, occurs throughout the active season, and sometimes elicits audible sounds from the males.

In mid-April to early June, when a female lays her clutch of as many as 14 eggs the size of Ping-Pong balls, the odds for survival are poor. If Gila monsters, kit foxes, badgers or coyotes don't eat the eggs, then 120 days later, when they hatch, ravens and roadrunners join the list of predators. Not until the tortoise reaches sexual maturity, at 7 to 8 years of age, does its shell harden sufficiently to withstand all but ravenous coyotes and feral dogs. Researchers estimate that only five of 100 tortoises will reach adulthood.

Upper respiratory-tract disease, a chronic infection, often proves fatal to the tortoise. Even if it doesn't succumb to the disease, an infected tortoise is a carrier for life and will infect other tortoises. The disease can decimate a local tortoise population.

Habitat degradation also poses a significant threat to the tortoise. Its inhospitable landscape attracts off-road vehicles and offers new opportunities for housing and industrial development. Against such encroachment, the desert tortoise has no options-it must move aside.

Like the hare in Aesop's fable, I have underestimated the tortoise. While I paused to think, it has disappeared ahead of me. Let's

hope it doesn't disappear altogether. AH

WAS WILL

Knowing the yarn-spinning reputation of Willie Drannan.