“We could call that a cold case, right? There’s no evidence, there’s no murder weapon… It’s a crime scene, but the perpetrator – the criminal – has left.” Biologist Karen Lips‘s opening words in the 2023 animated short: “The waiting”, predict a mystery with far-reaching consequences.
The award-winning film, directed by Volker Schlecht and written by Alexander Lahl and Max Mönch, follows the mysterious disappearance of tree frogs in Costa Rica. Using a hand-drawn, mostly black and white style, rainforest creatures transform from plants, turning small tadpoles into full-grown amphibians.
In the 1990s, Lips conducted research in the Costa Rican rainforest, stationed in a small hut the scientists called “la casita,” where she monitored a group of fluorescent green tree frogs.Isthmohyla calypsa. The species possessed unique points on their hands that were used as weapons to physically fight for dominance in the habitat.
For almost two years she studied the Isthmohyla calypsa‘s growth patterns, behavior and habitat, before returning to the University of Miami to write her research. When a final experiment prompted her to return to the forest, she discovered that the frogs had disappeared. “All of them,” she says.
At first, Lips wondered if the disappearance was the result of something she had done. Were they scared? Had she bothered them too much? Maybe there wasn’t enough rain? “I thought… maybe I just have to wait long enough and they’ll come back,” she says.
After waiting all summer, the frogs never appeared again. She was determined to solve the mystery, but there was no more evidence to study. “There was no smoking gun,” says Lips. Eventually, she moved to another location to study a new set of frogs. But after a few days, her team started noticing unusual skin problems.
The culprit turned out to be microscopic fungi known as chytridsand it was not limited to the mountainous cloud forests of Costa Rica. Researchers in countries around the world reported similar findings when Lips shared her concerns.
While it is impossible to say how the frogs initially came into contact with the fungus, humans bear responsibility for their fate, and ultimately that of many other creatures. The more we import and export food and other biological goods, the more likely it is that invasive – and sometimes dangerous – organisms will spread. “We’ve made it super easy for all kinds of infectious diseases to leave the jungle and reach a major city in a few hours,” she says.
The consequences for frogs alone are significant: “It is estimated that somewhere between 150 and perhaps 200 species have become extinct in the past twenty to thirty years,” says Lips. “Forty-one percent of all amphibians are declining. And that is worse than any other group of animals on the planet.”
Read more about the film at Instagram.
