A fungal disease that is devastating many amphibian populations around the world causes some infected tree frogs to sing more, even though they don't show other symptoms.

Credit: Jungbae Park

Amphibians are threatened by a global pandemic of chytridiomycosis, which is caused by the chytrid fungus Batrachochytrium dendrobatidis. Deuknam An and Bruce Waldman from Seoul National University recorded the mating calls of male Japanese tree frogs (Hyla japonica; pictured), before testing them for the fungus. They found that infected males tended to call more rapidly, and produce longer calls, than non-infected frogs.

This could be a sign that the fungus is manipulating the frogs' behaviour — longer calls attract more frogs, potentially spreading the disease. Alternatively, the frogs could be mating earlier because of a shortened lifespan.

Biol. Lett. 12, 20160018 (2016)