New Species of Tree Frog with Unique Shrill Calls Discovered in Costa Rica

A naturalist from Costa Rica who was exploring the new shrill calls he heard discovered a new species of tree frog.

The tiny, mostly green tapir valley tree frog, or Tlalocohyla celeste, has red spots and blue armpits. The frog was first described in a recent paper published in the journal Zootaxa.

Unique Shrill Call

Donald Varela Soto, the co-owner of Tapir Valley Nature Reserve, became curious when he first heard the weird shrill calls that came from a frog.

Soto, the lead author of the study, said that Country boys are familiar with sounds, and because he was raised in the country, he spent his childhood exploring the forests and learning to recognize different tree, bird, and frog species.

He listened to this tiny frog, but it was so well hidden that he had a hard time finding it.

Soto was overjoyed when he discovered it because, for six months after first hearing the strange shrill call, he had been searching for the frog making it.

About four years ago, while he was working near a pond following the first significant rainfall of the year, he heard the frog for the very first time.

He had to discover the source of the noise because it was so distinct.

Valeria Espinall, a biologist who helped spot the frog, said that In the wetland at night, there are about 16 different frog species that all have distinctive calls, so Soto started listening and observing them.

A particular shrill call seemed to be present in great quantities.

When Donald turned around to look, he saw the same tiny green frog.

The frog, which only measured two centimeters long, was virtually invisible because it was so well concealed in the tall grasses.

Its main color was green, and its features included red spots, blue armpits, and a yellow line that partially ran down its sides.

Stalking Frogs at 4 AM

Tadpoles, which help identify the genus, were sought after by researchers to determine how distinct the species was from other related frogs.

They can describe the entire life cycle and learn what habitat the frog needs to survive by finding tadpoles.

They were unsure which species belonged to the new frog since there were so many others in the wetland.

Finding frogs in the amplexus, or the position where they are mating, and then following the female until she lays her eggs, is the best way to be certain.

Months of nighttime searching failed to turn up the frogs in their mating embrace. They decided to search for them early the next morning.

Juan Abarca, a herpetologist, said that one day, instead of leaving at dusk, as usual, they left as early as 4 AM to see if they were lucky.

Just as dawn was breaking, they found the first amplexus ever recorded for that species, and, to their great luck, they were just about to lay their eggs.

They were overjoyed by their discovery because it allowed them to confirm the process of egg-laying.

Hiding in Plain Sight

The frog was discovered in a former cattle ranch that had suffered from extensive cattle activity and deforestation.

It was converted into a nature reserve by Soto and his fellow owners.

According to Espinall, Soto intended to remove all the cows and restore the original landscape to create a popular destination for ecotourism without realizing a new species was present nearby, Treehugger reported.