Tiny brazilian toad that stopped hydroelectric dam faces new climate challenge after devastating floods

In the forests of Rio Grande do Sul, Brazil, a thumb-sized amphibian has become an unlikely environmental hero. The red-bellied toad (Melanophryniscus admirabilis) made history in 2014 as the first amphibian to successfully halt the construction of a hydroelectric dam that would have destroyed its only known habitat along the Forqueta River near Arvorezinha.

This remarkable species, found nowhere else on Earth, lives in a small refuge called Perau de Janeiro—a hidden sanctuary of wet rocks and humid forest surrounded by tobacco plantations and pastures. With only about 1,000 individuals in existence, it ranks among the planet’s rarest and most endangered species.

However, the little toad that once stopped industrial progress now faces a different threat. In 2024, catastrophic floods devastated Rio Grande do Sul in what became the state’s worst climate disaster on record. These extreme weather events, intensified by climate change, have researchers deeply concerned about the survival of this endemic species.

In October 2025, nearly a year and a half after the floods, scientists returned to the toad’s unique habitat to assess the damage. Their mission was critical: determine whether this conservation success story had survived the destructive force of the floodwaters. The team ventured down steep trails into the misty, moss-scented refuge where waterfalls cascade through rock formations, listening carefully for the distinctive calls that would signal the species’ survival. The fate of this tiny amphibian serves as a powerful reminder of how climate change threatens even our most celebrated conservation victories.