In the rainforests of Madagascar, it can feel like you’ve stepped into another world. The air hums with life, dense with the sounds of birds, insects, and rushing streams. But if you listen closely, you might hear something even stranger — a faint, high-pitched whistling sound that seems out of place, almost otherworldly.

These whistles belong to seven newly discovered species of tree frogs from the Boophis genus, tiny creatures living among the tangled vines and misty mountaintops of Madagascar’s rainforests. Their calls, which resembled sound effects from Star Trek, not only helped the researchers identify them as distinct species but also inspired their names: Kirk, Picard, Sisko, Janeway, Archer, Burnham, and Pike — after some of the most iconic captains of the sci-fi franchise.

“Not only do these frogs sound like sound-effects from Star Trek, but it seems also fitting that to find them, you often have to do quite a bit of trekking! A few species are found in places accessible to tourists, but to find several of these species, we had to undertake major expeditions to remote forest fragments and mountain peaks,” explains Assistant Professor Mark D. Scherz from the Natural History Museum of Denmark at the University of Copenhagen, the study’s senior author.

“There’s a real sense of scientific discovery and exploration here, which we think is in the spirit of Star Trek.”

Frogs That Whistle in the Dark

Most of us know frogs by their croaks. But these frogs, it turns out, have a whole different method of communication. Instead of croaking, they whistle. It’s not a soft, melodic whistle either. It’s sharp and clear, slicing through the cacophony of sound in their rainforest homes. The calls are often emitted near fast-moving streams, where the roar of water drowns out most other noises.

“The appearance of the frogs has led to them being confused with similar species until now, but each species makes a distinctive series of these high-pitched whistles, that has allowed us to tell them apart from each other, and from other frogs,” said Dr Jörn Köhler, Senior Curator of Vertebrate Zoology at the Hessisches Landesmuseum Darmstadt, Germany

What makes the discovery even more striking is how these calls allowed the researchers to distinguish between the species. For years, the frogs’ appearance had caused confusion. Their greenish-brown skins and similar sizes led scientists to believe they were just different populations of the same species. But their whistles told another story. Each species makes a unique series of whistles — some of which are eerily similar to the famous ‘tricorder’ sound effect from Star Trek. When paired with genetic analysis, the researchers were able to confirm that these were, in fact, seven distinct species.

A Fragile World

Madagascar is a place of biological wonders, an island brimming with life forms that exist nowhere else on Earth. It’s home to around 9% of the world’s frog species, and new discoveries are made frequently. But there’s a dark undercurrent to these findings — many of these species, including the new tree frogs, live in habitats that are shrinking.

“We’ve only scratched the surface of what Madagascar’s rainforests have to offer. Every time we go into the forest, we find new species, and just in terms of frogs, there are still several hundred species we haven’t yet described,” said Professor Andolalao Rakotoarison of the Université d’Itasy in Madagascar, who over the last ten years has helped describe 100 new species on the island.

The frogs are particularly vulnerable. Many live in close proximity to one another but at different altitudes, thriving in very specific conditions. A slight shift in temperature or rainfall could push these delicate creatures to the brink.

It’s a discovery laced with both excitement and urgency. The researchers hope that by naming these frogs after beloved characters from Star Trek, they might draw attention to the need for conservation in Madagascar. These frogs might sound like they’re from a different planet but their future is very much tied to ours.

The findings appeared in the journal Vertebrate Zoology.