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.”
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.