Turtle Ninjas

Gregg Treinish and his team at Adventurers and Scientists for Conservation bring us stories from around the world about adventuring with purpose. Here, ASC naturalist guide Nikki Mann writes about her experience with the “turtle ninjas” working to save sea turtles on the magnificent beaches of Costa Rica.

By Nikki Mann

These are not sword-wielding turtles moving through the shadows of society to defend humans.

These are flashlight-wielding humans moving through the shadows of society to defend turtles. They often work alone, usually at night, wearing dark clothing. They work long hours for little or no pay, and even less notoriety. They do it for the turtles.

A turtle ninja collects data on every nesting female sea turtle, including her shell width, length and the numbers on her flipper tags if she has them. (Photo by Nikki Mann)

Until our recent trip to Costa Rica scouting an ASC Guided Outing, neither my partner Jeff nor I had any idea this underground army existed. A reserved Costa Rican native named Oscar Brenes, who seemed as much a general naturalist as highly trained biologist, was the first turtle ninja we met.

“Hear that sound?” Oscar asked. “That’s an antbird.” He pointed into the impenetrable jungle in Reserva Playa Tortuga, a privately owned, protected forest on the south Pacific Coast, just north of the Osa Peninsula. A few moments later, the cryptic black antbird flashed out from the shadows and was gone again.

Oscar led us through enormous palm fronds and waxy green philodendrons to the public beach. We stopped just shy of the ocean at the turtle nursery, which had enough beach sand to build a raised nursery, but remained out of sight from poachers.

Jeff Wohl records jaguar tracks on the beach. Jaguars are among one of the many predators of sea turtles, which also include human poachers. (Photo by Nikki Mann)

A Reserva Playa Tortuga staff member is here at all times, either sleeping in bug netting on a raised wooden platform during the day, or walking the beach at night collecting eggs from arriving turtles before the poachers can find them.

That night we walked the beach from 10:00 p.m. to 1:00 a.m. with Cami, a Reserva Playa Tortuga staff ninja. Flashes of lightning brightened the otherwise black beach.

“Who are these poachers anyway?” I asked. “Are they dangerous?”

Cami’s long blond hair was the only part of her I could see as she turned to answer. “Not dangerous,” she said, “not really.” Her English was hesitant—but she’s from Switzerland and speaks a fair bit of Spanish in addition to several other languages.

“I was in town the other day… and there was a little girl selling turtle eggs. What could I say to her?”

What indeed. Locals have been eating turtle eggs as a delicacy for generations. Some make an illegal living selling the eggs; others don’t realize how collecting a few nests impacts turtle populations.

The best estimates are that one baby turtle in 1,000 will survive long enough to reproduce. Nest success rates vary widely depending on area, tides, temperature, abundance of predators, and other factors including fungus, crabs, vultures, jaguars, coati and humans.

A few days later we traveled south to the Osa Peninsula and visited a more remote beach at the Osa Conservation Center’s Piro Station. We spent the day with Manuel Sánchez, a thin turtle biologist with a broad smile, which sobered in concentration as we watched him carefully expose the remaining eggs black vultures hadn’t eaten yet.

Manuel Sánchez, turtle biologists at Osa Conservation’s Piro Station, places exposed turtle eggs carefully into a bucket for relocation further down the beach to a safer location. (Photo by Nikki Mann)
Manuel Sánchez, turtle biologist at Osa Conservation’s Piro Station, places exposed turtle eggs carefully into a bucket for relocation further down the beach to a safer location. (Photo by Nikki Mann)

Manuel gently placed the soft, squishy, golfball-shaped eggs into a bucket to be relocated to a safer location down the beach or removed to the hatchery. He explained that nests like this one, laid between the high-tide line and river, were guaranteed a partial or total nest failure when the tide shifted the river’s course and exposed them.

“We don’t have poaching problems here,” Manuel said, looking down the long strip of palm-fringed sand. “Although they do over there,” he said, pointing to a hazy beach visible in the distance.

A new turtle born in a hatchery is measured for shell width, length and weight. This helps biologists determine the success of their artificial hatchery versus wild nests hatched on the beach. (Photo by Nikki Mann)
A new turtle born in a hatchery is measured for shell width, length and weight. This helps biologists determine the success of their artificial hatchery versus wild nests hatched on the beach. (Photo by Nikki Mann)

We were fortunate that day because the high tides had forced us to look for nests in the daytime, rather than the usual nighttime prowl. However, because sea turtles almost always nest at night, we had missed the opportunity to collect the eggs as they were being laid.

Instead, hours later in the bright tropical sunshine, we had to follow the wide swath of turtle tracks to each nest, and spend a lot of time carefully excavating the eggs before they were washed away as the river shifted its course during the next high tide.

“We have a 90-percent success rate,” Manuel said proudly, gesturing to the nursery, which was covered in bird netting and sectioned off into squares with string grid-lines.

Each artificial turtle nest was further protected from crabs by wire mesh and insect netting. Half were shaded, the other half in sun, in an attempt to produce an even number of male and female turtles. A temperature difference in the nest chambers of only a few degrees determines turtle sex.

After a few days on the Osa Peninsula, we traveled 10 hours up the Pacific Coast to an even more remote beach in Santa Rosa National Park. This was a place we had access to only because we’d come with a biologist from the Osa Peninsula, who himself was there by invitation.

In Santa Rosa National Park, we met the ultimate turtle ninja—a turtle master. Wilbert is a short, muscled Nicaraguan field biologist who has worked with turtles for 16 years. He has been based at this remote field station for four years.

His workday starts at 8:00 p.m., when he follows a path through the mangrove forest, bright orange and purple crabs darting out from under his feet. Once on the beach, he spends the next eight hours walking back and forth across one kilometer of sand, tagging, measuring and sometimes taking tissue samples from sea turtles, as well as marking nests for data on success and failure rates. He doesn’t move any nests to keep poachers out, because there are none here. He is the only person, other than the occasional invited visitor or some of Santa Rosa’s park rangers, who will ever walk here.

This is a sacred beach: an arribada beach.

A Spanish word meaning “arrival into port or harbor,” an arribada is an event where tens of thousands of turtles arrive on a particular beach to nest on a single day. There are only two beaches in Costa Rica where this occurs.

turtles en mass
After tunneling their way out of 45 centimeters of sand, baby Oliver Ridley turtles head for the pounding surf and dangerous ocean, redefining the word “courage.” (Photo by Nikki Mann)

This beach is vitally important for conservation and protection, and also for science. The data collected here will help track population numbers, and, via the tissue samples Wilbert collects, help scientists learn where these animals spend their time in the ocean.

As we sat around the picnic table, Wilbert wrote out numbers, and with a little translation help, explained that when the beach was discovered in the 1980s, the estimated number of turtles that came during arribada was around 150,000.

The Wednesday before we arrived, 28,000 turtles came to nest. The reasons for such drastic declines are not well understood, but turtle ninjas like those we met are working to learn more.

Every day during the nesting season—and in some places like the Osa, every day of the year—they will be out in the dark, often on their own, working for very little pay or volunteering. They will get exhausted, bitten by no-see-ums and, in some locations, watched by jaguars hunting the turtles. The beaches will be beautiful, haunting and lonely.

And still they will be out there, night after night, for the turtles.

Nikki Mann and her partner in adventure, Jeff Wohl, have been ASC guides for three years. When they aren’t working in field biology or teaching natural history, they can be found planning their next epic trip. Learn more about Adventurers and Scientists for Conservation Guided Science Outings at adventurescience.org/guided-outings.

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Meet the Author
Gregg Treinish founded Adventure Scientists in 2011 with a strong passion for both scientific discovery and exploration. National Geographic named Gregg Adventurer of the Year in 2008 when he and a friend completed a 7,800-mile trek along the spine of the Andes Mountain Range. He was included on the Christian Science Monitor's 30 under 30 list in 2012, and the following year became a National Geographic Emerging Explorer for his work with Adventure Scientists. In 2013, he was named a Backpacker Magazine "hero", in 2015, a Draper Richards Kaplan Entrepreneur and one of Men's Journal's "50 Most Adventurous Men." In 2017, he was named an Ashoka Fellow and in 2018 one of the Grist 50 "Fixers." Gregg holds a biology degree from Montana State University and a sociology degree from CU-Boulder. He thru-hiked the Appalachian Trail in 2004. Read more updates from Gregg and others on the Adventure Scientists team at adventurescientists.org/field-notes. Follow Adventure Scientists on Instagram @adventurescientists, on Facebook @adventurescientists, and on Twitter @AdvScientists.