In an article in The New York Times on Wednesday, I write about how the fortunes of big solar power plants in the desert Southwest can hinge on the way developers handle imperiled wildlife in the path of their projects.
The protected desert tortoise has become the totemic animal for environmentalists fighting to ensure that the huge solar farms don’t eliminate essential habitat for the long-lived reptile and other wildlife, like the bighorn sheep and flat-tailed horned lizard.
The tortoise has been in decline for decades, and the rampant changing of the desert — including the development of casinos, strip malls and subdivisions, and designation of off-road recreational vehicle areas — took its toll long before construction began late last month on the Ivanpah solar power plant, the first large-scale solar thermal project to be break ground in the United States in 20 years.
Still, the solar farms will industrialize the desert on an unparalleled scale. The seven projects already licensed in California will cover 42 square miles with immense mirror arrays.
But as much as some biologists fear that the need to generate electricity without carbon dioxide emissions will harm the desert tortoise, the projects offer an opportunity for intensive research on the critter. That’s because regulations require solar developers to monitor tortoises for three years after they are relocated.
“Certainly the monitoring of the translocated desert tortoises will yield useful research information on the ability of desert tortoises to adapt to new surroundings,” Larry LaPré, a wildlife biologist with the United States Bureau of Land Management, said in an e-mail.
Such data is critical. While environmental regulations and efforts by developers like BrightSource Energy, the builder of the Ivanpah project in Southern California, are tailored to remove the tortoise from harm’s way during construction, the survival of the animals depends on how well they adjust to their new homes.
The track record on tortoise relocations is not encouraging. In 2008, more than 700 tortoises were moved from the Fort Irwin military installation in Southern California so the base could expand. Nearly half the relocated tortoises died within two years from, among other things, predation by coyotes and ravens, according to state records.
Biologists I met recently at the Ivanpah power plant site were far more optimistic about the relocation of 23 tortoises found in the project’s first phase.
“The tortoises at Fort Irwin were moved a lot further than these, and there also was a big problem with predators there,” Peter Woodman, a biologist who worked on the military project, explained as he stood by a holding pen where the Ivanpah tortoises will live until they are moved next spring.
“We’re hoping that by just moving these tortoises less, basically over the fence, that they will know where they are and where to go and they’ll habituate more easily,” he said.
Every tortoise captured at Ivanpah has been outfitted with a radio transmitter and given a health examination. Biologists will also radio-tag tortoises at a control site across a highway from the solar project so they can compare the movements and health of the relocated reptiles to those in a natural setting.
“We’ll learn a lot of things about the animal’s home range, whether the animals are in trouble at all and if there’s issues of the animal trying to get back into the site,” said Mercy Vaughn, the lead biologist on the Ivanpah project.
Dr. LaPré, the government biologist, said, “It may be possible to learn how the translocated tortoises interact with the residents.”
“For example, resident males may attempt to make the translocated males leave, or the translocated males may find a resident female, or uninhabited areas may be better than areas containing resident tortoises,’” he said. “We may actually learn something quantitative about the carrying capacity of desert habitats with different vegetation types.”
Ms. Vaughn, whose passion for the desert tortoise is clear, appeared conflicted about the need to move the tortoises from their homes of centuries.
“It’s tough to see it, but at the same time, we understand why it has to happen,” she said after happening upon an injured tortoise she said had been hit by an off-road recreational vehicle. “What’s appalling to me is that you can criticize a project like this, which is for the better good of the whole situation of humanity, while we still allow something really tragic like off-road vehicle activity to occur in large areas of the Mojave Desert.”
Karen Douglas, the chaiworman of the California Energy Commission, which licenses large-scale solar power plants, said the best way to avoid conflicts between renewable energy and desert tortoises is for developers to choose areas not favored by the animal.
“The toughest, most controversial projects picked sites that were harder to permit because they had wildlife impacts,” she said.By TODD WOODY/NYT