Can 3D-printing technology save threatened desert tortoises?
Tim Shields has always been a reptile freak. And his favorite reptile is the tortoise. As a biologist, Shields spent 35 years tracking populations of desert tortoises in the Mojave Desert.
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“They’re very sophisticated animals,” he said. “They have a different way of expressing intelligence. But, my god, the places they can survive in that would just fry you and me within two days, they make a hundred-year life out there. Only the best tortoises are [in the Mojave Desert]. The inferior and the unlucky just get filtered out really quickly. So I admire them. And every old adult that’s hacked it for 60 or 70 or 100 years just is so admirable simply for their persistence and their obvious talent being tortoises.”
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But those old-timers are getting thinner on the ground. Habitat encroachment by humans and predation by ravens have decimated tortoise populations. The California state reptile is listed as “threatened” by the Endangered Species Act and “vulnerable” by the International Union for Conservation of Nature.
“I spent 35 years basically watching tortoises go down the tubes,” Shields said. “And the last 10 have been ‘what can I do about it?’”
His best answer is using advanced technology.
Shields’ company Hardshell Labs, Inc. sells humane bird control services to industries. But its heart is in conservation. In March, Hardshell got a $255,414 National Science Foundation Small Business Innovation Research grant. He’s going to use it to further develop a defense system against ravens: weaponized “techno torts.”
“The stoutest testament to my love of tortoises is that I no longer spend very much time with them,” he said. “I spend all my time trying to solve the raven problem so that we’ll still have tortoises on the planet.”
The problem with ravens
Shields traced the raven problem back to a human population boom in the Mojave starting right after World War II. The numbers track to about a one-to-one population growth relationship between humans and ravens.
“It’s because ravens are just really good hitchhikers on the way humans transform a landscape,” he said. “A raven couldn’t ask for a better buddy than modern human beings.”
In addition to feeding off human-generated waste, ravens found desert tortoises to be an appealing and easy-to-catch snack. Early in Shields’ career, he started monitoring a three-square-mile plot of land to chart tortoise numbers. In 1979, his three-person crew found 590 tortoises on that patch. By 1989, that number was down to 220, and in 2002 it bottomed out at 40.
“At the start, the ravens were playing chess with us, and we weren’t even aware that there was a chess game going on,” he said.
But in the last 10 years, he’s honed in on raven strategies, priorities and behaviors. Now, it’s time for raven reeducation.
Meet the techno torts
“Ravens have learned that tortoises are tasty and easy to kill,” Shields said. “We want to change their mind about that.”
Hardshell Labs worked with Autodesk and Think 2 Thing 3D scanning and printing companies to create a realistic, life-size baby tortoise that can fight back. When ravens tap at its shell and try to turn it over, the faux tortoises spew out a cloud of methyl anthranilate. Ravens and other birds find this nontoxic grape flavoring repulsive.
Techno torts come in a variety of sizes, just like real tortoises. The reusable, weaponized version is made from hard 3D-printed resin. Other techno torts are non-weaponized and made from sandstone to simulate how a real tortoise shell breaks. These passive torts further convince ravens that the faux shells are real. Additionally, it allows the Hardshell Labs team to better understand their predation behavior by showing where on the shell they like to peck, such as flipping the tortoises on their backs and pecking at the underbelly.
Last year, Hardshell experimented with five weaponized techno torts, which Shields moved from place to place. This year, they’re putting out 20. Shields wants to test them near raven nests housing known pairs of ravens who are desperately trying to feed their growing babies. They’ll also chart the attack rate on the passive version and see if it goes down after the ravens encounter the weaponized torts.
“To the degree they show their young how to hunt and what to eat, they’ll probably teach their young, ‘Stay the hell away from those things, you never know when one’s going to blow up in their face,’” Shields said. “And even if they’ve eaten tortoises all their life, suddenly one out of 10 is blowing up in their face, they may similarly think twice before eating a tortoise. That’s the bet.”
Gamification and the future
Shields credits a team of engineers with turning his visions into lifelike tortoise decoys. And he’s thinking about how to take the experiment a few steps further and involving the public by gamifying the techno torts.
Gamers would have a tortoise-eye view of the raven attacks and could even trigger the spray. Shields is also considering robotic techno torts that gamers could control. Gamers could make the tortoise walk and try to provoke a raven attack.
“Humans have habituated to the guilt message in environmentalism and now tend to ignore it,” Shields said. “But the joy circuit in human beings is infinitely hungry for happiness… Video games are feeding our hunger for joy. And environmentalism ought to do that. My goal is to make the act of saving the world the most fun thing in the world.”