Testing a raven-repelling laser in the Mojave Desert. The beam, which doesn't harm its targets, has a range of roughly a mile. Photo: Tom Fowlks

Conservation

Meet the Bird Brainiacs: Common Raven

Tortoise biologist Tim Shields is trying to keep an endangered species from being eaten by ravens—without harming a feather in the process.

Editor's Note: Members of the crow family, known as the corvids, are among the smartest birds in the world. Some are capable of using tools, playing tricks, teaching each other new things, even holding “funerals.” And yet there’s still much we don’t know about these fascinating, sometimes confounding creatures. What’s going on inside the mind of a corvid? Three leading scientists are finding answers.

Tim Shields | Common Ravens (below)

John Marzluff | American Crows 

Nicky Clayton | Eurasian Jays  

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After more than three decades working as a desert tortoise biologist in the Mojave, Tim Shields began experiencing uncontrollable impulses to chase Common Ravens. While walking tortoise plots he’d surveyed for years, he’d see a black blur drop to the ground a half-mile away. His mind would flash on piles of palm-sized, picked-clean tortoise shells beneath electrical towers, and he’d tear off in a frenzied, and inevitably doomed, attempt to prevent the would-be killer from snatching one of his beloved subjects. “I’d run toward it like some crazy, possessed man,” he says. “I couldn’t stop myself.”

Shields had become morbidly convinced that ravens would finish off the ancient animals in whose company he’s now spent 38 of his 60 years. As a young field grunt decades earlier, he would see 80 or more tortoises a week. He documented males head-bobbing and ramming each other in testosterone-fueled frenzies, females munching on magenta beavertail cactus flowers, couples copulating in the morning sun. The creatures were already in decline at that point, largely due to habitat destruction and the pet trade. At the same time, raven populations were swelling.

If witnessing the torts’ slow decline was disquieting, what happened next was devastating. A respiratory disease spread through tortoise populations in the late 1980s, and by the early 2000s the illness had slashed most of those populations by 80 percent or more. The disease eventually waned and tortoise protections increased, but Shields’s surveys continued to turn up the raven-pecked shells of juveniles, each broken carapace another blow to the species’ survival. At one site in 2000 his team found 30 live tortoises and 398 carcasses. “All I was doing was taking careful notes on a quiet catastrophe,” he says. “It broke my heart. I knew I had to find some way to deal with ravens.”

Whatever way he found would have to be nonlethal: Ravens are protected under the Migratory Bird Treaty Act. Besides, Shields views harming the birds, which he calls “sentient creatures,” as unethical.

Shields is dogged and curious, and engagingly eccentric. He spends much of his spare time performing with a puppet troupe, and when he’s out in the field he often channels Vinny, a desert tortoise that speaks, bafflingly, in Brooklynese. (“It’s like a scene from da boyds out hea tudday,” he’ll say upon seeing 500 ravens roosting on a power line.) When he heard that someone was using a laser to humanely shoo geese from an airport, he had to track the guy down. He knew nothing about technology when he cold-called Pete Bitar, CEO of Xtreme Alternative Defense Systems (XADS), which produces nonlethal weapons, including wireless tasers. But Bitar, who started out in the Styrofoam-recycling business, agreed to fly from Indiana to California on his own dime to test the laser rifle on ravens (Shields cleared the test with the U.S. Fish and Wildlife Service). “One shot and they scattered,” Shields says. “It was beautiful.”

Tim Shields, with his laser, is on a mission to protect desert tortoises from predatory ravens. Photo: Tom Fowlks

Still, the laser alone didn’t constitute a strategy for battling ravens; it wasn’t practical to have ever-present sentinels deployed across the desert, ready to pull the trigger whenever a bird threatened a tortoise. Then one night over dinner, months later, Bitar mused that he had a funny idea: “What if we put a laser on a ledge and let people shoot pigeons?” He laughed it off, but the offhand comment inspired in Shields a middle-of-the-night epiphany. He bolted awake with a clear vision: a Doom-like video game in which users haze ravens with lasers attached to remote-controlled tortoise robots, fending off attacks in real time. He would recruit a legion of couch potato conservationists to the cause.

Shields knows it’s a highly speculative venture. Not to mention a rather ironic mission for someone who views shooter video games as “violent and idiotic.” But he has poured much of his life savings into his startup, Hardshell Labs, and has managed to cajole a crew of uber-nerds—Adobe and Apple engineers, NASA contractors, video game designers—to contribute their time and expertise to his quixotic quest. Most were recommended by an existing “speculative associate,” as Hardshell’s collaborators call themselves, and then bombarded with emails and calls from Shields.

Which is what happened when Bitar suggested Shields reach out to Roy Haggard, whose credentials include developing a radar test system for a Mars Rover lander. “Tim pestered me until I said yes,” says Haggard. “I like tortoises, but it would never occur to me to spend my time on this if I didn’t think it had huge potential.” Even if the laser and other emerging technologies Hardshell is investigating never morph into the addictive eco video game Shields envisions, if any prove commercially viable, they could have far wider applications than safeguarding tortoises. Dozens of species of protected birds devour crops or strike airplanes, racking up expensive damages and management nightmares. “We are on a technological binge, and that’s not going to change,” Shields says. “Why not try to make the most of it?”

The way Shields sees it, the tortoises simply need a break. They’re resilient creatures that have roamed the Southwest for millions of years, adapting as what had been a shallow inland sea transformed to desert. Human development, which began in the 1940s, proved harder to withstand. Ravens followed close behind people, as they tend to do, using electrical towers and other structures to nest, roost, and perch. The unfussy eaters thrived on garbage but also enjoyed the easy pickings of young tortoises, whose plodding pace is no match for the acrobatic flyers and whose shells, until about age five, are too soft to fend off raven beaks. Today the bird and the tortoise overlap across more than 60,000 square miles. It’s a scene playing out with other species elsewhere in the West, where ravens prey on Greater Sage-Grouse, Marbled Murrelets, and Least Terns. Rather than attempt to battle the birds everywhere they occur, Shields aims to create raven-free zones, a square mile or so each, in critical areas. That should, he says, allow some young torts to get through the gauntlet.

A California desert tortoise gets in close for a look at the Hardshell Labs rover. Photo: Tom Fowlks

The tricky part is convincing ravens to turn down calories. Like their urban-dwelling crow cousins, they’re incredibly intelligent and resourceful. Ravens raised in captivity can learn to mimic human speech. In the wild they cooperate and learn from one another. Pairs at seabird colonies work the crowd like experienced grifters: One bird distracts an incubating adult while the other swoops in and snatches the exposed egg or chick. They sometimes hunt larger prey in groups, like winged wolves. No surefire tools exist to deter the tricksters from a food source, whether it’s trash, nut crops, or baby tortoises. “In 25 years I haven’t seen anything make a dent,” says William I. Boarman, a tortoise and raven biologist who has worked for multiple federal agencies.

Boarman ticks off the options: Wildlife Services, the federal agency with the authority to take protected species, could kill ravens. Mass poisoning, however, needlessly kills large numbers of birds that aren’t troublemakers, and new birds simply move into the void. As for the other deadly approach—shooting birds with telltale tortoise shells scattered beneath their nests—nobody has ever done follow-up studies to see whether new tortoise snatchers take up residence. Then there are nonlethal controls, none of them particularly successful. Set off propane cannons, shoot blanks, or use disco-ball-style light shows, and the birds withdraw, watch, and then, once they realize there’s no actual danger, return.

“Tim is the most creative person trying to solve this situation, and it’ll be great if the avenues he’s pursuing work,” says Boarman. “Even so, I’m skeptical.” Ravens might prove too intelligent to trick, and tortoises might be too far into the danger zone or spread out too far to save.

There are other groups investigating innovative, nonlethal avian deterrents. In Alberta researchers are firing lasers at oil sands tailing ponds to try to prevent ducks and geese from landing on the deadly water. Scientists in California are painting chicken eggs greenish-blue and adding black spots to resemble eggs laid by endangered Marbled Murrelets, intentionally giving predatory Steller’s Jays food poisoning in the hopes they’ll lay off the real thing. Dutch engineers are developing drones to scare birds from airports. Yet, of all of them, Shields may be having the most fun.

Tim Shields with a drone, one of a number of technologies being tested as bird deterrents. Photo: Tom Fowlks

Early one September morning, Shields and biologist Al DeMartini, a Hardshell speculative associate who helps run the laser rifle trials, hunker down in a narrow crevice atop a bluff with the laser from XADS. The weapon is the most advanced product Hardshell is investigating, and the first one Shields will test during a three-day visit to the western Mojave. A thousand feet away, ravens trickle into the tidy black rows of compost at American Organics, a facility in Victorville, California, that processes food waste collected from greater Los Angeles. The birds seem oblivious to the steady boom of propane cannons—deterrents the company is legally required to use to try to keep ravens off the 10-acre smorgasbord. “Right now this is Shangri-la for ravens,” Shields says. “We want to make it hell on Earth.”

Five months earlier Shields and DeMartini conducted an eight-day trial here, firing the laser at set intervals and conducting counts every 20 minutes. The first day they tallied almost 600 birds. By the eighth, that number had dropped to the teens.

Today Shields, bouncing with nervous energy, asks DeMartini for a count. “We got 66 on the rows, 340 in the trees,” DeMartini reports with the confident ease of an experienced birder. “Rambo time?”

“Let’s do this,” Shields says, lifting the boxy rifle and lining up the sights. Bitar’s company designed the TALI TR3 to dazzle and disorient pirates in the Indian Ocean without hurting them; at 200 feet it poses no harm to human vision. It puts out three watts of green light, which means the beam extends about a mile. Shields fires at a bird pecking at compost. A dim fluorescent green beam silently appears in the bright sunlight. There’s no dramatic Star Wars-esque crackling whoosh or pew-pew-pew. (If it’s ever incorporated into a game, the company might need to add sound effects to satisfy players.)

Rover controls and a tablet for remote monitoring. Photo: Tom Fowlks

The bird’s reaction, however, is plenty dramatic. It whirls into the air the instant the dot touches its belly, like an action-flick character diving for cover upon spotting the red laser aiming dot from an enemy’s rifle. Nearby birds flee the chow lines, too, warned by their neighbor’s behavior. Shields gives a joyful whoop and sweeps the cottonwoods, the laser dot dancing across the greenery. In minutes the trees are empty of all but a handful of ravens. A few dozen circle overhead. Over the next two hours a couple hundred filter back in. By the third morning, about 200 birds show up, half that of the first day. The stalwarts are jittery. A passing train lifts dozens temporarily into the air. “Ooh, they’re spooked,” says Shields. After a few shots most of the birds exit the area completely, not bothering to circle.

Nobody knows for sure why the laser scatters ravens, says John Marzluff, a University of Washington corvid expert. (To read about Marzluff’s work with crows, see “The Cave Man.”) He suspects the birds perceive the beam as a solid stick appearing out of nowhere, or maybe feel mild heat. “Whatever it is, they’re probably thinking, ‘I don’t know what just hit me; I’ve got to get out of here,’ ” Marzluff says. The startle effect ripples throughout the flock, spreading the message that the laser is something to avoid.

Marzluff says innovative nonlethal tools are essential to prevent the “unsustainable and unethical” killing of ravens. But he stresses that Shields must prove that ravens don’t become habituated to the laser. Otherwise it’s no better than a propane cannon.

Shields is working on it. He’s collecting data at several other sites, including a pistachio orchard and roost, and expanding to other avian species and alternative laser colors. If the technology pans out, Stephen Fettig, a wildlife biologist with the U.S. Fish and Wildlife Service’s Migratory Bird Program, thinks it would be in high demand. “There are so many ways protected birds can sometimes be nuisances,” he says. Fettig asked Shields for a demo on herons and egrets gobbling fish at a Northern California aquaculture facility. He was staggered to see a few quick shots displace all but one of the dozen or so birds. “The high power, high accuracy, human control, and short duration of the laser make it very different than anything else I’ve seen,” he says. “Of course, it still needs to be proven. Lots of startups look like they’re going to make millions, then they fizzle.”

Shields is well aware of the uncertainty. “It could go really wrong,” he says. “But things out there are really wrong. The cliff is coming up fast.”

Rover developers Roy Haggard and Chris Smith with their creation and a captive tortoise. Photo: Tom Fowlks

Between laser trials, Shields trots out other potential products, including a drone on loan from a company called Aeronautical Sports League. He wants to see if drones could possibly monitor and haze ravens. The virtual reality goggles he dons allow him to stay out of sight, so the birds don’t associate the orange, four-propeller machine with a person. The drone sends 50 ravens flying when it gets to within about 50 feet. Shields is tickled but wonders if the goggles’ video resolution could be improved. Next he pulls out one of the new 3-D tortoise shells AutoDesk, the international software giant, is printing for Hardshell. The ersatz carapaces are so realistic that they initially fooled Boarman, the skeptic. This spring he’s putting the shells out at 40 camera traps to measure raven predation. Shields, meanwhile, is already planning to take the faux shells to the next level: He raised funds via a Kickstarter campaign to add raven-detecting sensors to the shells, and to see if tainting them with a nontoxic repellent convinces ravens that torts make terrible snacks. (Vinny, the tortoise puppet, is the face of the online fundraising efforts, lending a wry, whimsical bent to video updates.)

The main focus, however, is a rover prototype that may be the predecessor to a tortoise-sized vehicle that would roam among the reptiles. In the video-game scenario, remote rover operators might get points for spotting tortoises and predators, and noting interesting behavior, while their laser-operating teammates rack up points for repelling ravens. Today rover and tortoise will meet for the first time ever.

The rover that Roy Haggard and his computer programming guru Chris Smith have built looks like a $100 radio-controlled toy truck with a cheap Samsung camera phone attached. Which is exactly what it is, plus a whole lot more, explains Smith, an engineer whose resume includes developing next-generation 911 routing and dispatch systems. Although the duo is accustomed to working with six-figure budgets, they have turned the roughly $25,000 Hardshell has raised into a highly responsive vehicle that anyone on the planet can operate via the Internet—all with cellphone conferencing software and clever hacks to other existing technology.

Ravens take flight after being dosed by the XADS laser. Only a few shots, aimed at a few birds, were required to clear this massive, 4,000-bird roost at a food-waste composting facility near Victorville, California. Photo: Tom Fowlks

Shields removes a six-inch-long captive tortoise from a box and sets it beside the rover. Haggard and Smith duck into a utility shed with the controls. In the cramped space, they hunch over Haggard’s laptop, squinting at the small screen. Haggard has the rover control and Smith the one for the camera phone, which tilts, rotates, and provides the video. The tortoise eyes the vehicle for a few moments, ambles over, and, to everyone’s delight, licks a wheel. Then, apparently losing interest, it wanders off, the rover following close behind for an hour. There’s one mishap: The rover accidentally runs over the seemingly unperturbed tortoise, launching a discussion about adding a proximity sensor that activates a brake, like those in cars. Also, the video resolution is a little noisy, and the second-long lag time between the control and the rover is irksome. “With $100,000 we could fix that,” says Smith with a sigh. “I have the phone numbers of the two best guys in the first-person viewpoint technology domain,” says Haggard. “I’d like to talk to them about this, see what they suggest.”

Shields is elated at the rover’s progress. But later, after going over the highlights of the three days, he becomes unusually glum. “I know I look like a giddy kid in a toy store out here,” he says, his blue eyes brimming with tears. “I would trade it in a nanosecond to go back to 1979 and see 10 or more tortoises a day.”

He sits quietly for a few minutes, then sighs and stands up. It’s time to get back to work—and into character. Vinny has a video progress report to record. 

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