In Southern California’s Mojave Desert, ravens are increasing in number and preying on baby desert tortoises, decimating populations.
Hardshell Labs has developed a solution: a 3D-printed, baby-tortoise-size “Techno-Tort” that lures the birds then deters them with a puff of methyl anthranilate, more commonly known as grape flavoring.
Preliminary studies show it’s working, with a 46% reduction in raven return. Hardshell Labs has received a grant from the National Science foundation and a Roosevelt Genius Prize to continue its work.
In the Mojave Desert of Southern California, the raven population has exploded, thanks to the easy sources of food and water that come with human development. Essentially, humans are subsidizing the ravens’ needs: Trash and roadkill are their food sources; irrigation, water runoff, and artificial lakes and ponds provide water; and buildings, power poles, and billboards provide nests and shelter.
Ravens are now considered an invasive species in the desert and as their population increases, so does their need for new food sources. This massive increase in ravens has decimated the desert tortoise population—now at risk of extinction. Unfortunately, the ravens are preying on baby and juvenile tortoises, whose shells are still too soft to provide protection from a hungry raven’s beak.
What can be done to save these important reptiles? Conservation biologist Tim Shields and engineer Frank Guercio have found an answer: the Techno-Tort.
Shields and Guercia work for Hardshell Labs, of Joshua Tree, CA, and have designed and 3D printed the Techno-Tort, a conservation technology device that looks like a real tortoise shell, using Autodesk Fusion 360. But it contains something birds despise: methyl anthranilate, more commonly known as grape flavoring. When the raven’s beak pecks the Techno-Tort, an accelerometer triggers the device to release a quick burst of the chemical, deterring the raven from further destruction. Shields and Guercio call this “aversive training”—the idea is that if enough ravens peck at enough Techno-Torts, the ravens will stop preying on the real tortoises. Preliminary studies show that this method is working.
Watch the video to see the Techno-Tort in action and learn more about this important conservation effort.
Tim Shields, conservation biologist, Hardshell Labs: I always knew I wanted to be a field herpetologist. I met a tortoise when I was 14—a wild tortoise. That was my first one and it really struck me. I stumbled into this role as a tortoise research biologist as a consequence of spending 30 years on the same project, whose focus was to track population changes—well, the population changes were all negative.
[Shields points to a sign about the desert tortoise and begins reading it aloud.] “The natural area has about 200 tortoises per square mile.” It does not. That [sign] is nostalgic to me.
It was right off the bat that we knew ravens were killing a lot of baby tortoises. There’s so many ravens, and so few tortoises now, that the odds of a juvenile tortoise making it in the West Mojave are pretty dim. There’s a fairly simple mathematical relationship. More humans equals more ravens equals fewer tortoises. For years, my technology for raven control was chasing after them and throwing rocks at them.
We had this idea of, how do you make a fake tortoise? And then I meet this crazy kid, Frank Guercio, who just has this incredibly absorptive mind. I provided the impetus—try to make a convincing fake baby tortoise—and he took off with that.
Frank Guercio, engineer, Hardshell Labs: If I were going to describe the field or the industry, I guess you could call it “conservation technology.” It’s new. It hasn’t existed before now. In my tenure with Tim thus far, I’ve built tortoises, I’ve built rovers, I’ve built egg oilers and lasers. I’ve produced tortoises of different sizes and different shapes and different species. I love this stuff.
If I’m not 3D printing, if I’m not solving these problems, if I’m not designing, I get hives. I can’t stay still. If I want there to be tortoises in the future, as a designer, I have to find the solution.
Shields: The driving force behind this project is aversive training. There is a chemical called methyl anthranilate—it’s artificial grape flavoring. For whatever reason, artificial grape flavoring drives birds crazy, including ravens.
Guercio: The idea is that on the inside of either of these [Guercio holds two 3D-printed tortoise shells], we have a bladder.
Shields: As soon as [the Techno-Tort] gets hammered on, there’s an accelerometer that says, I’m being hammered on, so that at this very moment when the raven’s beak is right in here, all the sensitive tissues are right there. The thing just goes poof, like that. Our bet is that it’s going to be a sufficiently terrible experience. The raven is taught to leave live tortoises alone. Dealing with ravens, you got to be careful because if they figure out what the game is, the game is over. I have always erred on the side of greater accuracy—a more convincing fake baby tortoise.
Guercio: This is printed at a resolution of roughly 50 microns, or one 500th of a millimeter.
Shields: This is startling progress, and that’s because he just won’t let it rest. It’s really good to work with obsessives.
Guercio: Being able to import really complex geometries like an organic shape, like a tortoise, is very difficult to do in any sort of industry program. When it comes to the tortoise specifically, there was so much legwork on the back end to get it into a position where I could then mechanically edit it as an object. [Autodesk] Fusion 360 has been a fantastic tool. The second I became familiar with Autodesk products and really had them available to me, it really opened up the floodgates. We can create structures inside of the tortoise that was next to impossible about five years ago.
Shields: If a certain number of ravens have the bad experience with the Techno-Tort, we should see a reduction in the frequency of attacks.
Guercio: Having seen tortoises get ripped limb from limb, and then seeing one fight back was really cathartic. I’ve always been a member of the Mojave, and it is a harsh and unforgiving place. But this is where I found myself. We’re sitting in a space that three months from now is going to have 100 printers, filament production lines, resin printers, CNC machines, laser cutters, anything and everything that can be used to solve the problem. How many kids up here have access to a 3D printer or an opportunity to work with the Bureau of Land Management or save the tortoise? Leveraging this opportunity with Tim to save the world and species into having an immediate effect on my locale, I think that’s just the first step.
Shields: We already think we’re having a positive effect.
Guercio: We’re almost at this jumping off point where we’ll be able to apply what we’re creating here to the rest of the world’s problems, too.
Shields: Conservation biology is a pretty hopeless endeavor generally right now. So the provision of hope to the conservation community is really important to me personally.
Guercio: There’s nothing more satisfying—nothing in the world—than seeing something that you’ve made make a difference.