Aggressive responses to rivals depend on the interaction between the vocal traits of territory-holder and mimicked intruders in a miniature tropical frog
Territory defence is an important aspect of animal behaviour, and tightly linked to rival assessment and species recognition processes. An important component of these two processes is signalling, and animals must decide how to respond to a challenge based on the signals they perceive from their rivals. Here we manipulated the note repetition rate of rocket frog calls to simulate rivals with high and low vocal performances, and tested the aggressive responses of males in the field. We found that the probability of aggression depended on the interaction between the stimulus treatment and the peak frequency of the territorial males. Low-frequency calling males were more likely to respond aggressively to the fast call, while high-frequency calling males showed a higher probability of aggression towards the slow call. Frogs that responded aggressively approached the slow call 2.4-times faster than the fast call. Low-frequency calling males also increased their peak frequencies in response