3D Printed Turtle Shells Could Help Save This Endangered Species
If you’re wandering around the Mojave Desert and come across a desert tortoise, don’t dig too close to the creature — you might find yourself covered in a surprise spray of artificial grape fluid. It would be because this turtle is a 3D printed impostor and thinks you are a crow.
Thanks to human activity, crows have invaded the deserts of the western United States, wreaking havoc on its ecosystems and threatening the desert tortoise in particular, preying on juveniles before their shells are fully formed. . In an effort to save people, a biologist has teamed up with engineers to forge a 3D-printed lookalike baby turtle that allows them to collect data on crow attacks and counterattack with non-toxic spray. He hopes that the “techno tort” partnership can serve as a model for other biologists to solve certain conservation crises.
Crows are considered a invasive native species. They have proliferated by 700% over the past 25 years due to increased human presence in the desert, providing opportunities not previously available in the harsh environment: road accidents and litter are now food, while billboards display and transmission towers are nesting structures. Tim Shields, a field biologist with more than 30 years of experience studying turtle behavior and populations, zoomed in on a call with Fast Company from his car outside Victorville, Calif., at the southwest end of the Mojave Desert. “I look at a landscape that has been transformed,” he says. “I don’t look at anything but opportunities for crows.”
Crows eat well. They feast on burrowing owls; the colorfully named Coachella Valley Fringe-toed Lizard; and on young turtles, which crows eat by poking their beaks through soft shells when the turtles surface to escape scorching ground temperatures. They have no choice but to emerge: in the spring, juvenile turtles must come out and eat to help ossify their keratin shell, as the bone will make them more immune to long-term predation. But by doing this for 8-15 years of their childhood, then they risk attacks from crows. Desert tortoise populations have declined by at least 90% since the 1980s and are officially classified as threatened— even though Shields says they should be in the endangered category.
Enter “Techno Crime”, a counterfeit turtle made to trick crows. The concept has been underway for over a decade per Hardshell Laboratories, the Shields company that uses technology to protect native wildlife from bird damage. It was the ingenuity of a native Alaskan high school student from Shields that led the team to 3D print a shell, which was then enhanced by Autodesk, a software company that is one of the leaders in computer-aided design (CAD). Hardshell used the CAD tool, Fusion 360, to 3D print a hard plastic resin shell, painted to look like the baby critters. They turned out to be realistic. “I fool professional biologists with these things all the time,” Shields says. “I am wrong.”
It was crucial for them to be realistic in order to fool the crows. Imitation turtles can track crows foraging on them with their internal sensors and cameras, and collect data on when, where and how the crows attack, and the severity of the threat. Previously, Shields’ research relied on random dead shells, which was forensics rather than “scientifically rigorous demonstration,” he says. They deployed these shells en masse in 2018 and 2019 and sold around 1,000 to the US Fish and Wildlife Service. Using data collected from their fake turtles, Shields’ team determined that a single crow per 2.5 square kilometers in the desert will ensure localized turtle extinction. “The odds of this little guy escaping detection by a crow, in the time period it takes to mature, are basically nil,” Shields says.
Now some of the fake wrongs are fighting back. Cornerstone Research Group, a defense equipment manufacturing company, installed electronic accelerators and liquid canisters inside the hulls. If crows get aggressive, the shells will spray a non-toxic irritant called methyl anthranilate, an artificial grape flavor that repels birds. “Crows don’t like surprises,” Shields says, citing their high degree of neophobia, or fear of novelty. The idea is that they “shock the bejesus out of them, so that it gets burned into their brains”, and hopefully communicate the danger to their little ones. “We’re basically trying to insert a meme into crow society, and hopefully it will catch on,” he says.
[Photo: Hardshell Labs/courtesy Autodesk]
Hardshell is currently testing the performance of the armed prototypes in this “sting operation”, having tested 5 last year and 10 more this year. Shields is energized by collaboration and believes technology is the way to combat growing conservation disasters. On the other side are engineers who often work on dry issues, but are energized by turtles. “Autodesk went gaga over this,” he says. “They are so cute.”
For years, Hardshell has targeted crows with other technological solutions, including using laser lights to deter them from their habitats, and a procedure they call “remote egg oiling.” Nozzles mounted on aerial drones apply a non-toxic oil to the crow’s eggs, which prevents oxygen exchange so they don’t hatch. But they remain intact, so the crows continue to incubate them and do not re-nest, which contributes to reduced breeding and reduced populations.
The next step will be to get ahead of the curious crows by making the mannequins even more deceptive. “When you’re dealing with an animal as intelligent as a crow, you don’t want to bet everything on the animal’s current behavior because it’s very flexible,” says Shields. He wants to make a robot turtle that can move, or whose head can stick out and wiggle. The team may also consider other aversive tools, including meat baits dipped in a chemical called carbacholwhich would trigger a nasty food poisoning, a visceral reaction that is enough to keep us away from tasting certain foods.
He had fun making techno crimes a game. From a distance, players could control booby-trapped shells and potentially trigger the irritant. “Environmentalism based on the joy of games is a winner,” he says. “Environmentalism based on feelings of guilt is a loser.” Ultimately, he wants to find the best tools to get people off their screens and back into nature, and get them to care about conserving it. “Any game a human can build is a pale shadow of what ecosystems do all the time,” Shields says. “We should be madly in love with this planet.”