Finally: A robot that provokes male frogs enough to start a brawl.
That engineering triumph brings hope to Peter M. Narins of the University of California, Los Angeles. He and his colleagues have been trying to decode the communications of the brilliant-thighed dart-poison frog, Epipedobates femoralis, but they couldn't get the frogs to finish an interaction.
Males of this tiny tropical species stake out territories on the forest floor. Within their domains, males climb atop a log or other object and belt out calls. When Narins recorded the calls and played them back, males readily hopped toward the sound. That's where the experiment stalled. Males approached but didn't attack.