Frogs Have Learned to Cry for Sex in Urban Sewers

The Mien-tien tree frog's scientific name is Chirixalus idiootocus, but maybe it's not such an idiot, after all. For the diminutive croaker has mastered a skill that must be unique in the animal kingdom – exploiting the acoustics of concrete sewers to make booty calls.

A rare peek into the sexual habits of urban frogs comes from Wen-Hao "Bob" Tan and colleagues at the National Taiwan University, who spent many enlightening evenings in Taipei peering down drain holes at amorous idiootoci. After conducting experiments on location with a speaker and microphone, they made two conclusions: the amplitude and duration of mating calls are greater in the sewers – what they call "miniature urban canyons" – and the frogs were choosing exactly the right perch locations to maximize this effect.