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After hiding in the shadows, a long-lost frog is giving conservationists a glimmer of hope in Ecuador.
Back in 2022, biologist Juan Sánchez-Nivicela and his team navigated through dense vegetation on an expedition to the Molleturo Forest in the Ecuadorian Andes Mountains. At night, the researchers searched for new, rare, and lost amphibian species under the glow of the full moon with the Sangay volcano constantly rumbling miles away.
For a moment, the volcano’s noise briefly ceased, and the moonlight illuminated the glade of a fallen tree in the middle of the forest. The scientists approached it and found two tiny frogs that they couldn’t immediately identify. Last month, the team reported in Zoosystematics and Evolution that the frogs belong to the species Pristimantis ruidus. The International Union for Conservation of Nature (IUCN) had listed this species as “possibly extinct” because no scientist had seen it in the wild since zoologist George Tate originally discovered the frog in 1922.
“This discovery fills us with hope,” says biologist María del Carmen Vizcaíno, director of the Alianza Jambato, a coalition of more than 26 institutions dedicated to amphibian conservation in Ecuador. Vizcaíno, who was not involved in the new study, believes that P. ruidus could become a “flag of resistance” in the legal fight to protect the southern Andes—Ecuador’s most degraded ecosystem due to mining and illegal logging.
Juan Carlos Sánchez (pictured here analyzing a museum specimen in the laboratory) and his colleagues compared the P. ruidis frogs to other species to confirm the rediscovery.
Photograph by Jaime Culebras
Out of obscurity
In the 1970s, herpetologist John D. Lynch searched for and described several species from the southern Ecuador, but he never encountered P. ruidus. Instead, Lynch based his descriptions of the species on Tate’s preserved specimens, collected nearly fifty years earlier. In Sánchez-Nivicela’s laboratory at Universidad San Francisco in Quito, the team compared the wild frogs they collected to Lynch’s account.
The two frogs appeared just as Lynch had described and drawn them, with rough skin, many bumps and singular W-shaped ridges on their backs. Some frogs’ tympana or eardrums stick out from their heads, but not those P. ruidus—and neither did those of the wild frogs. “We went crazy,” Sánchez-Nivicela says. “It was perfect. The description matched perfectly.”
Researchers at the Universidad Técnica Particular de Loja also compared DNA from the two females with that of 35 other Pristimantis species preserved in a gene bank. The frogs’ genetic blueprint didn’t match any other species and confirmed the rediscovery. “It didn’t match anything because there was never any genetic material from this animal,” says Sánchez-Nivicela.
The rediscovery of P. ruidus is “a second chance to conserve what may potentially be the only locality where you can find it, not only in Ecuador but in the world,” says Diego Armijos Ojeda, a herpetologist at Universidad Técnica Particular de Loja. Armijos Ojeda was also part of an IUCN group that updated Ecuador’s Red List assessment of amphibian species in 2019, which showed that 363 amphibians are under threat—57 percent of the total species in the country.
Conservation battles
In November 2022, researchers set out to survey amphibian species in the Quitahuaycu Conservation Reserve in Molleturo, Ecuador. Here Ernesto Arbeláez Ortiz, another coauthor on the study, looks for tadpoles of another frog species also considered extinct.
Photograph by Jaime Culebras
Herpetologists and activists in Ecuador have leveraged amphibian rediscoveries to confront significant threats to the country’s biodiversity. In 2019, for instance, several conservation NGOs and northern Ecuadorian communities made Atelopus longirostris—a harlequin frog species rediscovered after 30 years—the symbol of their battle against mining concessions granted by the state to the Chilean company CODELCO and the national mining company Enami EP.
Activists and scientists warned that mining operations in northern Ecuador were violating the rights of nature and contaminating habitats near where researchers found A. longirostris. The conservationists filed a lawsuit, arguing that the environmental impact studies approving the entry of mining companies failed to account for the species inhabiting the Intag Valley in the north of the country. Moreover, the studies neglected to propose measures to protect endangered species like A. longirostris. After nearly five years of legal battles against the mining companies, a judge ruled in favor of the communities and NGOs earlier this year, revoking the Llurimagua mining project’s operating license.
“We won a battle,” says biologist Andrea Terán Valdez, a project coordinator for the Jambatu Center for Amphibian Research and Conservation in Quito. “The problem is that as long as the law remains the same, nothing will change,” she says.
The forests on the Andean foothills in western Ecuador, including the Molleturo Forest where P. ruidus reappeared, now retain only 30 percent of their original extent after two decades of intense deforestation, changes in land use and mining. Sánchez-Nivicela and his team are convinced that each species they discover and add to the list of amphibians strengthens their cause to protect the forest. In the laboratory, they will use the genetic material of Pristimantis ruidus to confirm whether other frogs belong to new or rediscovered species. Meanwhile, the researchers remain determined to find more amphibians believed to be extinct. “We have faith,” Sánchez-Nivicela says. “We think they’re still out there.”
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