California requires developers to provide two acres of suitable tortoise habitat for every acre of habitat taken. But the scale of the solar development coming to Western deserts is so vast that it renders the formula unworkable. Not enough alternative land exists.
Instead, solar developers may now pay to close off-road vehicle routes, rehabilitate degraded habitat on federal land, fund public education programs and erect miles of special fencing to keep the tortoises off highways and out of solar energy sites.
Tortoise relocation is a formidable issue. Moved animals nearly always attempt to plod home, piloted by an uncanny sense of direction.
"If I pick you up and drop you off in Kansas, wouldn't you try to come back to California?" Fesnock asked. Tortoises live long and have good memories, she said. "They know when they are not at home. They know where the water is. They know where the food is."
For now, wildlife officials are still unsure if they will release animals this spring because a drought is expected this summer.
To date, just one desert tortoise has been relocated at Ivanpah.
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Last October, a tagged female, BS-71, had been in a holding pen for four months and wasn't adapting. She endlessly paced her enclosure. Over and over the animal attempted to climb the wire mesh, gaining some height, then usually ending up flipping on her back.
Unable to bear the sight of the tortoise's apparent distress any longer, BrightSource lead biologist Mercy Vaughn sought permission to release the female to the wild. The request has since been dubbed the "Mercy Rule."
After gaining approval from the U.S. Fish and Wildlife Service, filling out paperwork, providing medical testing — a tortoise under stress is more susceptible to disease — Vaughn was finally cleared to free the homesick tortoise.
The animal was placed in a purple plastic bin and carried deep into the desert. While a dozen people looked on, some filming the event, the tortoise was gently placed at the entrance of a burrow. She hesitated for a moment, then shuffled down into the gloom.
Moments later BS-71 reemerged, blinked and began munching grass.
Times researcher Maloy Moore contributed to this report.
ABOUT THIS SERIES: This is the fourth in a series of occasional stories chronicling the wide-ranging effects on the West of the emerging solar-energy industry.