This is a story about a small nature reserve in northern Costa Rica that has been full of surprises.

In the early 2000s Donald Varela-Soto and Melvin Rodriguez bought a property located between two volcanoes (called Miravalles and Tenorio). They had a plan. They wanted to rewild the land, much of which had been turned into cattle pasture. They wanted to restore the land to its natural forest state.

Map of the Tenorio-Miravalles Biological Corridor, a matrix composed of cattle pastures, agricultural land, and small towns between the Tenorio Volcano National Park and the Miravalles Volcano National Park. Credit: Sofia Pastor-Parajeles

As the years passed, Varela-Soto and Rodriguez transformed their property into the 220-hectare (544-acre) Tapir Valley Nature Reserve. The reserve is marked on the map above, just north of the Tenorio Volcano National Park.

They removed the cows and they began restoring the fields into forest. In some areas, the pasture was left alone, allowing the wind and animals to disperse seeds from neighboring forests in a process known as natural regeneration.

One of the reasons they wanted to rewild the land was to connect habitat for wildlife, including the native Baird’s tapir. The Tapir Valley Nature Reserve now connects its forests with those of the nearby national parks, allowing animals to move between them.

The restored forest in the nature reserve has attracted a wealth of plants and animals from surrounding forests, including collared peccaries, jaguars, and Baird’s tapirs. The Baird’s tapir helps the forest grow by eating fruit and spreading the seeds when it poos.

Video: A female Baird’s tapir crushing Jicaro Danto fruits with its powerful jaw in Tapir Valley Nature Reserve. Video by CRWF-Nai Conservation ©.

In addition to tapirs and jaguars, Donald Varela-Soto discovered an animal in his nature reserve that he was not expecting.  

It started with a shrill call coming from the reserve’s small wetland.

The wetland in the Tapir Valley Nature Reserve. Image courtesy of Tapir Valley Nature Reserve.

“I kept hearing this different sound in the wetland but was unable to find it,” said Donald Varela-Soto. “Then, on a particularly rainy day, the water rose in the wetland, pushing the frogs out to the edges, and that’s when I saw it in person. It was like, wow, this is amazing! This is beautiful!”

Valeria Aspinall and Varela-Soto and watching a Tapir Valley tree frog in the wetland at Tapir Valley Nature Reserve, its only known habitat. Photo by David Vela Muñoz.

What he found turned out to be a new species, a tiny green tree frog that has been named the Tapir Valley tree frog:

Tlalocohyla celeste. Image courtesy of Tapir Valley Nature Reserve.

The brilliant-green frog is about the size of a bottle cap. It has a distinctive yellow line that runs halfway around its bright body.  Donald Valera-Soto and colleagues gave the frog the scientific name Tlalocohyla celeste in honor of the turquoise waters of a local river, the Río Celeste. A formal description of the species has now been published in the scientific journal Zootaxa.

A female tapir valley tree frog (Tlalocohyla celeste) is shown ready to lay eggs, which are visible through her semi-transparent skin. Photo by Valeria Aspinall.

The Tapir Valley tree frog may be critically endangered. Its only known habitat is the 8-hectare (20-acre) wetland within the Tapir Valley Nature Reserve. That makes the frog an endemic species to the reserve, known to live there and nowhere else on Earth.

The local biologists who worked on describing the new frog species (from left to right): Juan Abarca, Esteban Brenes-Mora, Valeria Aspinall and Donald Varela-Soto. Image by Marco Molina.

Watch this video to learn more about endemic species:

Activity: protecting and connecting habitat for frogs

Imagine that you discover a species of frog in your yard but that it needs more habitat than just your yard area to survive. How would you go about protecting this frog species and its habitat?

Things to consider:

What resources does the frog need? Think about food (such as insects), water, and shelter from predators.

How would you connect the frog habitat in your yard with other habitat areas that it needs? Perhaps you could talk to your neighbors and agree on protecting a habitat corridor for frogs that contains a network of ponds. A habitat corridor allows frogs to move between the resources they need.

Does your frog species need protection from predators like cats or chickens? How could you create a predator-safe corridor? Could you provide logs, leaf litter, and other shelter for the frogs?

Frogs have permeable skin. Their skin is sensitive to some chemicals like certain pesticides. How could you protect your frog’s habitat from pollution?

Parents/educators: here are some resources about creating frog-friendly habitats

Creating a frog-friendly habitat: ages 7-13, activity packet from Junior Landcare Australia

Learn more about frogs:

Adapted from a story by Liz Kimbrough, published on


Varela-Soto, D., Abarca, J. G., Brenes-Mora, E., Aspinall, V., Leenders, T., & Shepack, A. (2022). A new species of brilliant green frog of the genus Tlalocohyla (Anura, Hylidae) hiding between two volcanoes of northern Costa Rica. Zootaxa5178(6), 501-531. doi:10.11646/ZOOTAXA.5178.6.1

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