Photograph by Dr. Edgar Lehr
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The Humboldt's rubber frog is one of three new tiny frog species discovered in the Peruvian Andes.

Photograph by Dr. Edgar Lehr

Three New Grape-Size Frogs Found, May Already Be Threatened

Scientists discovered the mini amphibians in a remote forest preserve in Peru.

Don't blink—you might miss three new species of tiny frogs discovered in Peru. Scientists found the grape-size amphibians hopping about the Pui Pui Protected Forest, a remote and little-visited refuge that requires a two-day hike from the nearest city.

“We were the first scientists that entered to place to see what was living there, with a focus on amphibians and reptiles,” says study leader Edgar Lehr, a biologist at Illinois Wesleyan University. “Then I understood why nobody went there because it’s so difficult to access.”

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The Pui Pui rubber frog was named after the Pui Pui Protected Forest in Peru, where it was discovered.

Lehr and his team, who spent almost three months in the forest between 2012 and 2014, unearthed the frogs by combing through grass, rocks, moss and other small plants.

The newfound species are called the Pui Pui rubber frog, the Humboldt’s rubber frog—named for German naturalist and explorer Alexander von Humboldt—and the hill dweller rubber frog. (Read more about seven tiny frog species discovered in India.)

The frogs join nearly 500 known species of land-breeding frogs in the Craugastoridae family, according to Lehr, a National Geographic Society grantee.

Stumbling Upon a Tiny New Frog Species by Night

November 15, 2012—See how, late one evening in a remote Peruvian cloud forest, a National Geographic explorer happened upon a big little discovery—a new frog to go with seven other new species found during the expedition.

Deadly Fungus

While the frogs are fortunate to live in a protected area, they still face several threats, including habitat loss and climate change, says Lehr, whose study appears July 27 in the journal Zootaxa.

“You can only protect the fauna and flora once you know them, so you need to know first what lives there and then you can monitor population change and if species disappear,” he says. (See: Striking Yellow-Black Rain Frog Found, Is Already Endangered.)

The researchers in the Pui Pui forest took skin samples from the newly discovered frogs and found several had the fungus. (Read: “Deadly Frog Fungus Pops Up in Madagascar, An Amphibian Wonderland”)

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Pristimantis bounides

“Of course, we cannot know what this means at the moment for the species, but it’s important to record that the fungus is present there,” says Lehr.

'It Never Gets Boring'

Earlier this year, Lehr and colleagues described two other species of tiny frogs: the Attenborough's rubber frog and the Ashaninka rubber frog. (Read about the world’s smallest frog that is also the world’s tiniest vertebrate.)

During their three years surveying the forest, the scientists have found a total of 14 new species, including new lizards and more tiny frogs, which will be described in future papers.

“It’s very fascinating when you hold in your hands something that is new to science,” said Lehr. “It never gets boring.”

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The Pui Pui Protected Forest in central Peru is so isolated that it took scientists two days of hiking just to reach the border.