Animal displays are often perceived by intended and non-intended receivers in more than one sensory system. In addition, cues that are an incidental consequence of signal production can also be perceived by different receivers, even when the receivers employ different sensory systems to perceive them. Here, we show that vocal responses of male túngara frogs (Physalaemus pustulosus) increase two-fold when call-induced water ripples are added to the acoustic component of a rival’s call. Hunting bats...