Using intelligence of ravens to protect threatened tortoises

Tim Shields is a modern-day Renaissance man; a muralist with a mission. Shields is also a biologist and the founder and CEO of Hardshell Labs Inc., a conservation technology program attempting to repopulate desert tortoises in the Mojave, whose species has been preyed on by ravens.

“It’s very hard to find a tortoise in the desert anymore. I mean, I go days at a time on tortoise projects seeing no live tortoises, and when I started my career, that was not the case. I would see 10, 15 tortoises a day. Day after day. I can go 10 days without seeing one now,” Shields says.

Dr. William Boarman is the leading tortoise-raven biologist in the country. He says the raven problem has gone on for nearly 30 years.

“Ravens are by no means a demon, they’re by no means a bad bird, it’s just that they happen to be conflicting with the needs of another species that is in trouble,” Boarman says, “We found 250 tortoise shells underneath one nest over a four-year period.”

Boarman says tortoises typically don’t reproduce until they’re nearly 15 years old, which means 15 years of dodging predators to have a chance at expanding the population.

“Ravens and tortoises have probably always coexisted, but raven populations were probably at much lower levels, and there were lots of other foods for the ravens to eat, but human activities have greatly increased the raven populations,” Boarman says.

Shields and Boarman are now creating a tool kit of nonlethal technology, combating the ravens and putting a stop to what they call a desperate situation for desert tortoises.

The primary weapon in their arsenal are 3-D printed tortoise shells. Shields paints over each model to create a more believable look.

The plan for the fake tortoise shells is to fill them with foods known to make ravens nauseous.

“You don’t want to kill the bird, you want to train it. You want to give it pause so that when it sees this form, you want them to think not worth it. It might be one of those weird upsetting forms of tortoise,” Shields says.

Shields and Boarman are currently testing empty 3-D printed shells to see the level of interest from potential tortoise predators. They’re recording these interactions with motion-sensored cameras.

“We’ve had quite a few instances of ravens attacking or coming and checking them out. They’ll peck at them. We’ve had two or three that have been pecked open by the ravens. We’ve also had coyotes that have bit at them,” Boarman says.

“The beauty of it is we’re not only dealing with individuals that are really intelligent, but they have societal social networks,” Shields says, “They flock together and they talk together.”

Shields and Boarman hope to see word spread among adult ravens and lessons passed down over generations, changing the diet of the birds and removing tortoises from the menu.

Other tools that the biologists are using for their active ecological management plan include green light lasers, rovers and drones. They serve as makeshift body guards for tortoises, following them around and deterring ravens from snagging a bite.

“For me, I’m not concerned about saving every individual tortoise, because they’re an individual life that needs to be saved. I’m concerned about recovering the natural habitat to its natural state, and by helping the tortoises get to that poin,t it’s helping a lot of species. It’s helping the plants and the habitat in general.”