Mojave desert tortoises move toward extinction
CALIFORNIA CITY, Calif. — Behind the fences surrounding this 40square-mile outback of cactus and wiry creosote, the largest remaining population of Mojave desert tortoises was soaking up the morning sun and grazing on a mix of wild greens and flowers.
But that didn’t mean the armored beasts were easy to find in a tiny spit of sand that Congress voted to protect in 1980 and designated with a name only herpetologists could love: Desert Tortoise Research Natural Area.
After a few hours of searching in late September, naturalist Lisa LaVelle tramped down a narrow path — past thorny brush that hid rattlesnakes and scorpions — and fixed her eyes on a tortoise the size of a shoebox.
She scanned its carapace for a GPS tracker or an identification tag. After spotting neither, she smiled and said, “Well, hello there! I don’t believe we’ve met before.”
LaVelle, who is part of a team charged with monitoring the overall health of the area’s tortoises, was elated by the discovery. “We have one more tortoise than we thought we had,” she said. “That’s great news for us and a species that needs all the help it can get.”
Sadly, California’s state reptile is hurtling toward extinction. Crushing vehicle strikes, urban encroachment, hungry ravens, military maneuvers, disease, drought, extreme heat, wildfires, illegal marijuana grows and development of massive solar farms are all pushing the species to the brink.
Eight decades ago, the vast Mojave Desert was home to hundreds of tortoises per square mile, with tortoises inhabiting nearly all areas of the desert below an altitude of 3,000 feet. Today, most tortoise populations in California and outside designated recovery areas have fallen to two to three adults per square mile — too few for male and female tortoises to find each other and mate, researchers say.
It’s the type of precipitous decline that spurred state lawmakers to adopt the California Endangered Species Act in 1970. The landmark legislation — which grants broad protections to plant and animal species that are deemed endangered or threatened by the state Fish and Game Commission — predated the U.S. Endangered Species Act by three years.
“Over time, the California Endangered Species Act evolved parallel to and in a symbiotic relationship with the federal government’s,” said Brendan Cummings, conservation director for the Center for Biological Diversity. “They influenced each other in changes in substance and implementation of endangered species protections.”
While both laws have been credited with helping to rescue such charismatic avian species as the California
condor, bald eagle and peregrine falcon, global warming and human encroachment are outpacing the laws’ ability to safeguard certain plants and animals.
Although Gopherus agassizii was listed as threatened under the California law in 1989 and the federal law the following year, those protections have done little to improve the dire prognosis for the benign herbivores with weary eyes.
Hoping to reverse the very real likelihood that the species will become extinct, the Defenders of Wildlife, the Desert Tortoise Council and the Desert Tortoise Preserve Committee have filed a petition urging the California Fish and Game Commission to elevate its status from threatened to endangered. A final decision is expected later this year.
“With new climate change threats not foreseen when CESA was enacted, we have to do better,” said Laura Cunningham, California director at Western Watersheds Project, a nonprofit conservation group dedicated to protecting native species and restoring habitats they depend on.
State officials and conservationists acknowledge that there is no significant difference in the legal protections offered to species listed as threatened or endangered. However, endangered species have higher priority and funding for conservation measures such as public outreach, habitat protection,
recovery efforts and mitigation measures to compensate for habitat losses due to massive construction projects.
“Elevating the species’ status to endangered wouldn’t bring development in the desert to a halt,” said Jun Lee, director of the Desert Tortoise Preserve Committee. “But it would help raise funds for recovery efforts and make a big difference in getting developers to provide compensation for the habitat they disturb.”
California typically requires developers to provide two to three acres of suitable tortoise habitat for every acre taken. Solar developers may pay to close off-road vehicle routes, rehabilitate degraded habitat, fund public education programs, translocate tortoises, and erect miles of special fencing to keep the tortoises off highways and out of solar energy facilities.
But efforts to meet California’s
ambitious energy goals have heightened conflicts between the tortoise and large-scale solar energy facilities and electrical transmission corridors.
There are more than a dozen solar energy facilities operating in the Mojave Desert, and an estimated 15 more have been approved for development.
Under the current system, the cost of developing a comprehensive wildlifeprotection plan falls most heavily on the developer who had to undertake expensive mitigation, often with the help of biological consultants who are paid up to $1,000 per day to assist in capturing and relocating local tortoises to land set aside for them elsewhere.
Despite promises to do so, critics say, state and federal wildlife and land management agencies often fail to devote enough money and staff to ensure that all goes as planned, hastening the disappearance of a species that has been roaming Southern California’s desert for thousands of years.
At the $2.2 billion BrightSource Energy solar farm in Ivanpah Valley, just west of the Nevada border, construction was halted for three months in 2012 due to an unforeseen calamity: Excavation work found far more tortoises than biologists expected.
Although BrightSource had already spent $56 million to protect and relocate 166 adult and juvenile tortoises, some animals were squashed by vehicles, while ants attacked hatchlings in a makeshift nursery and an eagle carried off a juvenile tortoise as a microchip embedded in its shell pinged ever more faintly on its journey to the raptor’s nest.
Last summer, federal wildlife biologists relocated 139 Mojave desert tortoises from a solar farm that was under construction near Pahrump, in southern Nevada. Less than three weeks later, 30 of those tortoises were believed to have been killed by badgers, according to emails that conservationists obtained through a public records request.
Although sheathed like a battle tank, the tortoise was not well adapted to harsh, arid landscapes. It evolved millions of years ago when the region was cooler, wetter and dominated by lakes and marshes edged with Joshua trees and junipers, scientists say.