Site icon Conservation news

The turtle egg that pinged back: Tracing a poaching pathway in Costa Rica

Newly hatched olive ridley sea turtle in Costa Rica. Photo by Rhett A. Butler.

Newly hatched olive ridley sea turtle in Costa Rica. Photo by Rhett A. Butler.

  • A team of scientists has created 3D printed decoy sea turtle eggs, fitted with GPS trackers to follow the path of eggs stolen by poachers.
  • In a recent study on the first trial run of these eggs, the team confirmed that most poached sea turtle eggs are traded locally.
  • However, they also identified a much longer track — 137 kilometers, or 85 miles — that illuminated the pathway of what appears to be a much more organized trade system.
  • Mongabay followed the hour-by-hour track of this egg to understand why sea turtle poaching still happens, and to learn what experts think can be done to stop it.

Early on the morning of Sept. 16, 2018, an olive ridley sea turtle (Lepidochelys
) hauled herself out of the ocean along a beach on Costa Rica’s Nicoya Peninsula. Moving slowly, methodically, she started a task she had likely done dozens of times before: excavating a nest in which to lay her eggs. But then something new happened.

Just before 5 a.m., a team of scientists walking the beach crouched beside her, as the nest filled with eggs, and added something to it: a fake egg, fitted with a GPS tracking device that would follow the decoy if a poacher removed it from the nest.

A little over 24 hours later, that’s exactly what happened.

The clever egg decoy unearthed that day is a project of a team led by Helen Pheasey, a Ph.D. student at the University of Kent, U.K., studying the sea turtle egg trade in Costa Rica.

With the help of Pheasey’s team, Mongabay traced the hour-by-hour trip of the furthest-traveled of five decoys taken by poachers, in an effort to understand why sea turtle egg poaching still happens — and what experts think can be done to stop it.

A 3-D printed sea turtle egg decoy, which looks and feels like the real thing thanks to a substance called Ninja Flex. The eggs’ creators have since developed newer prototypes with even more realistic exteriors, and more reliable GPS trackers. Image courtesy of Helen Pheasey.

Monday, Sept. 17, 2018
Time: 7:27 a.m.
Corozalito, Costa Rica

The decoy egg came online in the small town of Corozalito, in the western Nicoya Peninsula. The person who removed the clutch of eggs had done so under cover of darkness, likely slipping the pingpong-ball-sized eggs into a bag or an improvised sling using their T-shirt.

Conserving sea turtles worldwide often starts here. Six of the seven sea turtle species worldwide are threatened, and while some regional populations are in much better shape than others, protecting eggs provides an easy and effective way to ensure sea turtle populations persist into the future.

“Sea turtles are slow to mature, and for some populations it is estimated this may take up to or over 25 years,” Pheasey said in an interview with Mongabay. “This is significant, as it means the damage of removing eggs today will not be seen for 25 years when the offspring of the ‘poached generation’ fail to arrive at their nesting beaches.”

Moving quickly to avoid detection, the poacher on that night in September didn’t notice that one of the eggs wasn’t quite like the others. That was thanks to Kim Williams-Guillén, director of conservation science for the nonprofit Paso Pacífico, who took on the challenge of creating the egg after receiving a grant to design a prototype from the United States Agency for International Development’s (USAID) Wildlife Crime Tech Challenge.

After a few failed experiments with plastic (too hard) and silicone rubber (too messy and complicated), she landed on a 3D-printed filament called Ninja Flex, which could be made to look and feel very close to a sea turtle egg. Inside, she embedded a cheap GPS tracker that pinged its location every hour off local cellphone towers.

The team wasn’t surprised that the decoy egg’s first ping came just a few miles from the beach where the real eggs were laid. Most poached sea turtle eggs are sold locally, often door-to-door as a seasonal treat. They’re also hawked in seaside bars, where the eggs are dashed with hot sauce and slurped down in a shot glass as a purported aphrodisiac. Indeed, most of the five decoy eggs traveled only a few kilometers; one moved only 28 meters (92 feet).

But this turtle egg was different. In its next ping, Pheasey’s team saw that it was on the move.

By fitting decoy eggs with a GPS tracker, Pheasey’s team was able to confirm that the majority of poached sea turtle eggs are traded locally, usually door-to-door. The eggs could help conservation teams strategize the best community intervention programs, which could help lift people out of poverty and offer alternatives to poaching for survival. Image courtesy of Helen Pheasey.

Time: 8:27 a.m.
Location: Ruta 21

The GPS tracker within Williams-Guillén’s decoys allowed the team to see how fast their eggs were traveling during their ping. By 8:27 a.m., the decoy was clearly in a vehicle, traveling north and inland. As the sun climbed in the sky, the landscape around the decoy egg would have changed, from palm-lined dark sand beaches, to two-lane roads through hilly forest villages.

With every mile the decoy traveled, it became increasingly apparent that the turtle eggs were leaving the hands of local poachers and going into a more organized system. This is an important distinction, according to Pheasey and Williams-Guillén. Most egg poachers along the coast live in poverty. Many are unable to find jobs. They poach and sell eggs to make enough money to feed themselves, or to keep up with substance abuse problems, Williams-Guillén says.

Williams-Guillén has frequently said her inspiration for the egg decoy came from the TV show The Wire, which featured an episode with a listening device inside a tennis ball. But she also sees the system most egg poachers exist in as analogous to the TV show. Like the kids in the show who are recruited to sell drugs, most egg poachers are motivated to illegal activity by survival.

“I don’t hate egg poachers, I really don’t, I just hate the system,” Williams-Guillén told Mongabay. “The economic system has placed them in a world where they can’t have a viable livelihood in a way that doesn’t involve natural resource extraction.”

Olive ridley sea turtles nesting on Escobilla beach in Oaxaca, Mexico. Photo credit Claudio Giovenzana via Wikimedia Commons (CC BY 3.0).

Time: 10:27 a.m.
Location: Pan-American Highway

Over the next two hours, the egg pinged twice on Route 1, the Pan-American Highway. It was now moving southwest toward Costa Rica’s capital city, San José. This was further evidence that the egg had moved from the local market into the world of organized crime. This may reflect a larger trend in the Costa Rican egg market, something that Pheasey is investigating for her Ph.D.: that the legal harvest of eggs along the coast may be buoying the demand for eggs elsewhere in the country.

On a single beach, within Ostional National Wildlife Refuge, locals are permitted to harvest eggs from the first wave of olive ridley nests every year. There, olive ridleys nest in such incredible numbers that they often dig up the nests laid by previous females, killing those earlier eggs in the process.

Pheasey is investigating how that legal trade affects poaching on nearby beaches, and whether illegal eggs are being laundered through the legal egg trade. Her decoys are just one step in examining this complicated question.

“Thanks to Helen’s work, what we see in Costa Rica is there is still poaching on the other beaches; [the legal harvest] has not done what it needs to do in terms of satiating the desire for eggs,” Williams-Guillén said. “So this is potentially having a spillover into other places. Other parts of the country, far removed from Ostional, are saying: let’s get some turtle eggs. And those could be coming from any place.”

The furthest-traveled decoy egg moved 137km, allowing the team to track what may be a full trade chain for poached sea turtle eggs. Image courtesy of Helen Pheasey.

Time: 11:27 a.m.
Location: San Ramon, supermarket loading bay

The egg’s next ping came from San Ramon, a town about 60 kilometers (37 miles) northwest of San José. When Pheasey saw that the egg had stopped moving, she zoomed into the map, and immediately knew: the egg was into something “dodgy,” as she put it. It was sitting in the loading bay behind a supermarket. Pheasey and Williams-Guillén think this is likely where the turtle eggs were sold to someone in a larger criminal effort, which consolidated eggs from multiple poachers.

This kind of discovery has important ramifications for how the decoy eggs might be used to reduce poaching in the future. Rather than use them to go after individuals selling eggs off the beach, they could help identify and shut down nodes within larger networks of egg trading. After all, if the poacher doesn’t have a place to take their eggs to, there’s not much reason to poach.

“You can jail every single kid on the corner slinging eggs, and another one pops up, because they’re not really the person who is in power or the decision maker,” Williams-Guillén said. “A lot of people see this and are like ah, they’re going to get the bad guys. But ideally what we’re going to do is use the information in such a way to intervene so that poaching is not profitable anymore.”

Jeffrey Seminoff, director of marine turtle ecology and assessment at Southwest Fisheries Science Center at the U.S. National Oceanic and Atmospheric Administration (NOAA), who was not involved with the decoy project, praised the decoy egg’s utility in uncovering these trade pathways.

“This is an all hands on deck phase of conservation, and something like this is so novel and such a wonderful marriage of technology and need,” Seminoff said. He said he would love to see a decoy for leatherback turtles, one of his focus species, which are critically endangered and also face the threat of egg poaching. “I think the exportability of this is just off the charts. If there was a Nobel prize in turtle technology, this would get it.”

An olive ridley sea turtle hatchling in Costa Rica. Photo by Rhett Butler.

Tuesday, Sept. 18, 2018
Time: 12:27 p.m.
Location: San Ramon, residential property

The egg’s final ping came from a home in the neighborhood around the supermarket, suggesting that it had moved through the hands of one of the sellers that offer sea turtle eggs door-to-door. The end user, for whom turtle eggs are a traditional, cultural food, presents the final — and possibly the most difficult — hurdle for conservationists.

“The best way to deal with that is take out the market, and have people refusing to eat the eggs. That’s obviously a really different challenge,” Pheasey said.

Jessica Kahler, an assistant professor at the University of Florida who studies the application of conservation criminology to wildlife crime, told Mongabay that many conservation efforts rely too heavily on education to try and stop people from eating wildlife. Yet the little research done on these efforts shows that they rarely effect any change in behavior.

“There has to be some really careful consideration in which we understand, for various users, what role is this food playing in their lives, and have different strategies for different people,” said Kahler, who was not involved in the decoy egg project. “We have to think strategically across the entire supply chain, and it’s daunting, when you feel very desperate to slow this down.”

Seminoff said he faced this challenge two decades ago while trying to reduce turtle poaching for meat in Mexico.

“If I had walked into a place at the time and said, you can’t eat any more sea turtle, it would be the same as someone walking into main street USA and saying, you can not have a hamburger,” he said. “[These products] have never been labeled as unethical before.”

His team started by encouraging fishermen to return just one turtle per trip. Fast forward to today, and Seminoff says many of these fishermen no longer eat or catch turtle, and help to spread the word about turtle conservation.

Similar community efforts are already underway in Costa Rica, where conservation groups that Pheasey works with have focused on helping to lift kids out of poverty rather than push a conservation message. The hope is that if kids stay in school, and can get better jobs in the future, they won’t have to resort to egg poaching for money. With time, perhaps, the demand for eggs will diminish too.

“It’s a slow, slow approach, laying foundations and engaging with the children and giving them opportunities,” Pheasey said. “These decoy eggs are just one example of a huge, multifaceted approach.”

Olive ridley’s sea turtle laying eggs. Image via Wikimedia Commons (CC BY-SA 3.0).


Pheasey, H., Roberts, D. L., Rojas-Cañizales, D., Mejías-Balsalobre, C., Griffiths, R. A., & Williams-Guillen, K. (2020). Using GPS-enabled decoy turtle eggs to track illegal trade. Current Biology, 30(19), 1066-1068. doi:10.1016/j.cub.2020.08.065

Banner image of a newly hatched olive ridley sea turtle in Costa Rica. Photo by Rhett A. Butler. 

Claudia Geib is the 2020 Sue Palminteri WildTech Reporting Fellow, which honors the memory of Mongabay Wildtech editor Sue Palminteri by providing opportunities for students to gain experience in conservation technology and writing. You can support this program here.