Heat-driven sex reversal in agile frogs threatens long-term survival

UPDATE - follow-up to Global warming is turning frogs' sex reversal into an extinction risk: new research shows that sex-reversed agile frogs in Hungary sire fewer offspring and face higher risks of population decline as temperatures climb. Published in Science Advances on September 3, the study reveals that excessive heat during the tadpole stage can override chromosomes to turn genetically female tadpoles into fertile males. While around 40 percent of amphibian species already face extinction risks, researchers found that wild sex-reversed male frogs made up roughly 20 percent of local populations but accounted for only 4 percent of egg clutches. Furthermore, 61 percent of their offspring also underwent sex reversal, compared to 17 percent of offspring from normal males. When exposed to artificial heat waves and the pathogen ranavirus, which can wipe out over 90 percent of tadpoles in a single event, the offspring of sex-reversed males carried higher viral loads. Computer models show that these combined pressures could drive small populations to extinction 60 to 70 years faster, with disease accelerating the timeline by nearly a decade.

Context

Amphibians are highly sensitive to environmental changes because of their permeable skin and aquatic life stages. Rising global temperatures increasingly disrupt their natural biological processes, threatening vulnerable ecosystems worldwide.