Overview

• Published Aug. 5 in Proceedings of the Royal Society B, the study confirms that male fiddler crabs dynamically adjust their display intensity in response to rival signals.
• The University of Exeter’s CRAB team engineered a Bluetooth-controlled, 3D-printed robot with interchangeable claw sizes to isolate the influence of competitor morphology.
• In Ria Formosa Natural Park trials, males extended waving when facing a smaller robotic claw but hesitated and retreated more frequently against a larger one.
• Aggressive individuals occasionally attacked Wavy Dave, dislodging its claw and terminating those trials, underscoring risk-assessment behaviors.
• These findings highlight the potential of biomimetic robotics in dissecting animal communication and competitive strategies in natural settings.