Group Threatens Lawsuit Over Last Best Mojave Tortoise Habitat

Two proposed large solar projects in the Ivanpah Valley in California and Nevada will do serious damage to desert tortoise habitat, and the U.S. Fish and Wildlife Service and Bureau of Land Management may violate the Endangered Species Act (ESA) if the agencies allow the projects to proceed. That's the message in a sternly worded legal notice delivered to USFWS, BLM, and the U.S. Department of the Interior last week by attorneys for the national environmental group Defenders of Wildlife.

In the letter, formally called a Notice of Intent, Defenders' attorneys say that USFWS issued a Biological Opinion (BiOp) greenlighting the Stateline and Silver State South solar projects near the Mojave National Preserve despite the fact that Silver State South would essentially close off a crucial genetic connectivity corridor through the Ivanpah Valley. The BiOp also approves a controversial plan to move tortoises away from the project site, which practice many tortoise biologists say harms tortoises more than helping them. And the BiOp doesnt account for the cumulative impact to tortoise habitat of the explosion of similar solar projects across the desert.

As a result, say Defenders' attorneys, if the Department of the Interior approves the projects without reexamining their effect on desert tortoises, that'll violate the ESA -- and Defenders is prepared to take the government to court to protect some of the last best remaining tortoise habitat in the Mojave Desert.

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The desert tortoise, Gopherus agassizii, is protected as a Threatened species under ESA. That makes it illegal to kill, harm, harass, or capture the tortoise without premission from USFWS, and "harm" is usually construed to include hurting the habitat the tortoise needs to survive as well.

As KCET reported in October, more than 2,000 tortoises may occupy the footprints of the two projects, which First Solar wants to build not far from BrightSource's Ivanpah Solar Electric Generating System.

Work on the BrightSource plant was famously halted in 2011 when workers started finding hundreds of desert tortoises on the site. The USFWS had anticipated that project would turn up about 37 tortoises, but was forced to amend BrightSource's BiOp to add another 1,100 tortoises to the project's allowable take.

In its amendment of BrightSource's BiOp back in 2011 to account for those hundreds of unexpected tortoises, USFWS stuck to its original assessment that BrightSource's project wouldn't impair the species' chances of survival. Why not? Because a wide genetic connectivity corridor still existed in the eastern half of the valley between the Silver State North solar project, then in the planning stages, and the Lucy Gray Mountains north of Nipton. As a Nevada representative of USFWS said in a 2012 letter to the BLM,

In the biological opinion for the Ivanpah Solar Energy Generation Station issued to BLM on June 10, 2011 (Service 2011), the maintenance of a suitable linkage between the Silver State Project and the Lucy Gray Mountains was a key reason why we concluded that connectivity would still be maintained after construction of that project.

That corridor would now mainly be sealed off by Silver State South.

Wildlife migration corridors for animals that move over long distances can often incorporate narrow bottlenecks and still be functional links between populations, as for example in the case of mountain lions trying to get to the Santa Monica Mountains. But tortoises don't migrate: they rarely venture more than a mile and a half from the place in which they were born. And the reptiles don't like to share their territories, allowing others into their turf only for mating. That means that keeping populations of desert tortoises connected to that genes can flow between them -- important to keep those populations robust -- you need uninterrupted tortoise habitat between them that's at least three miles across and preferably five or more, so that each part of the corridor can host two or more home ranges abreast through its length.

That's not just a wildlife-huggers' unpragmatic assertion: it's the sober recommendation of the USFWS itself. And yet in USFWS's BiOp for Stateline and Silver State South, the agency says it's no problem that the latter project would constrict the corridor along the Lucy Grays to less than a mile and a half wide, not enough room for even one tortoise lifetime range.

Compounding that loss of habitat is USFWS's seeming approval of a plan to move 100 tortoises from the Silver State South footprint into the same constricted area that's not wide enough for one home tortoise range. Translocation, or moving of desert tortoises out of their home ranges into new territory, is a controversial measure than has nonetheless become standard operating procedure for desert development projects. Opponents point to a disastrous 2008 translocation project involving tortoises moved from their home ranges on the U.S. Army base at Fort Irwin: within three years, half the moved tortoises were dead. Adult tortoises make full use of their decades of familiarity with the few square miles of territory to survive to desert's rigors: move them to unfamiliar territory and they die from drought, from predation, and from stress as they try to find their home turf.

Though some biologists have questioned whether the 2008 Fort Irwin experience is necessarily characteristic of tortoise translocations in general, no one disagrees that the process of being captured, handled, and moved is dangerous for the animals. And that risk doesn't just affect the tortoises that get moved to new places: new neighbors can cause serious stress in the local "host" population of tortoises, who find themselves fighting for territory, food and mates with the new arrivals.

According to the Defenders' Notice of Intent, USFWS's approval of the two projects is based on a "fundamentally flawed" translocation plan: the BiOp says that the 200 or so tortoises USFWS expects will have to be moved will enjoy "post-translocation survival rates [that] will not significantly differ from that of animals that have not been translocated."

Defenders points out that the USFWS is contradicting its own past statements here, among them comments by the agency on Silver State South's Draft Environmental Impact Statement, in which USFWS said it "does not support translocation as a proven minimization measure for development projects."

"We would be happy to discuss with [the agencies] any of the issues raised in this letter," concludes the notice from Defenders' attorneys. "However, unless the agencies commit that they will not rely upon the legally flawed BiOp and will act promptly [to] rectify the ESA violations set forth in this letter, our clients intend to seek appropriate remedies to insure the protection of the desert tortoise and its habitat as well as other species that will be affected by these ill conceived projects."

No lawsuit can be filed until Interior issues a Record of Decision on the projects, but that move is expected soon. If Defenders does sue, that will mark a bit of a departure for the green movement. Large national environmental groups have sued over desert solar projects' effect on wildlife before, but those suits have been reserved for the most destructive projects like the now-canceled Calico Solar. Larger groups have been loath to sue over projects in the Ivanpah Valley, relegating it to less-favored status because of existing development. Until now, it's been smaller, grassroots groups like Western Watersheds who've been going to court to defend the desert tortoises of the Ivanpah Valley.

But unlike many more undeveloped spots in the Mojave, the Ivanpah Valley -- even with its freeway, its gas power plant, and its clusters of casinos -- is still some of the best remaining tortoise habitat in the Mojave Desert. A national group like Defenders threatening to lawyer up may be some of the best news Ivanpah tortoises have had in a long time.

About the Author

Chris Clarke is a natural history writer and environmental journalist currently at work on a book about the Joshua tree. He lives in Joshua Tree.
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