Driving through Southern California’s Mojave Desert on a recent road trip, we stopped when we saw a sign for a desert tortoise environment, hoping we’d encounter some reptilian wildlife. Instead, old fire pits and lots of broken glass from people doing target practice on bottles. Not a tortoise in sight. This area used to be crawling with tortoises. But there’s been more than a 90% decline since Tim Shields started studying Mojave tortoise populations in the 1970s. Shields, a wildlife biologist and founder of Hardshell Labs, traces the tortoise decimation to World War Two. During the war, soldiers preparing to fight in North Africa trained in the Mojave. “This weird dry little corner of America became known to a huge number of people,” Shields said. Some of them settled in the desert after the war. Ravens followed, knowing that human habitation meant easy food sources. When they weren’t raiding trash cans, the birds feasted on juvenile desert tortoises. Now the Endangered Species Act lists the desert tortoise as “threatened,” while the International Union for Conservation of Nature considers it “vulnerable.”
Now Shields and his team at Hardshell Labs are counterattacking. They’ve invented the Techno-tortoise™, or technotort for short. These weaponized 3D-printed fake tortoises spray out noxious methyl anthranilate when pecked. Birds loathe the nontoxic but very yucky concentrated grape flavoring. Cameras inside the technotorts record the attacks. It’s still early days in the research, but the technotorts’ mission is to reeducate the ravens so they’ll leave juvenile tortoises alone.
In what initially struck me as strange conservation bedfellows, the Department of Defense is funding the technotort experiment. Shields explained that the DoD is responsible for stewarding a huge amount of prime desert tortoise habitat in the California desert. “Threatened and endangered species are a pain in the butt,” he said. The DoD would love tortoises to be removed from the threatened species list because their operating rules would ease. “There are some pretty funny instances where a tortoise gets in front of a convoy of tanks at Fort Irwin and the entire convoy has to stop and wait for a tortoise to cross the road.” Beyond the inconvenience, DoD biologists want to do the right thing.
“Nobody wants to wipe tortoises out,” he said. And because DoD folks are technophiles, they’re likelier to adopt an innovative technological solution than other agencies.
William I. Boarman, Hardshell’s science director and a raven expert, oversaw the latest round of technotort tests during this year’s spring raven nesting season. Boarman deployed ten weaponized technotorts, rotating them through different known nest sites for a week for a total of 31 locations. “Did the ravens get sprayed?” Boarman told me. “Yes. They hated it. They just split instantly.” He recorded nine raven attacks in the 31 locations. This figure was at the low end of his expected range, probably because drought meant high breeding failure and lots of abandoned raven nests. “So the big question still is, does this actually stop them from preying on tortoises?” Boarman asked. “And that we can’t answer right now. We need a bigger, more intensive, longer-term test.” He’s hoping that funding will come through for a larger study next year. And all of us tortoise lovers are hoping that someday desert tortoises trudging across the Mojave will once again be a common sight.