The tree frog die-off that sparked a global mystery – and revealed a dark truth

In the animated documentary The Waiting, Karen Lips, professor of biology at University of Maryland, College Park, chronicles a mysterious mass disappearance she encountered across two field studies in Costa Rica and Panama in the early 1990s. Framing the incident as a ‘cold case’, Lips recalls how, upon returning to a once-thriving ecosystem where she had researched the metamorphoses of Isthmohyla calypsa, a small tree frog, she was shocked to find that the creatures she’d been studying had disappeared. To tell the story, the German director Volker Schlecht pairs Lips’s words with meticulous sound design and flowing hand-drawn sketches that adorn biologically accurate images with impressionistic touches. Ultimately, the immersive work reveals a troubling global problem, against the background of humanity’s far-reaching, yet often unseen, impacts on nonhuman animal populations across the globe.