Bimodal signal requisite for agonistic behavior in a dart-poison frog,<i>Epipedobates</i><i>femoralis</i>

TLDR

Animal acoustic signals are crucial for mate attraction, territorial defense, and other social interactions, yet no single signal feature reliably elicits species‑specific behavior, as shown in the diurnal dart‑poison frog *Epipedobates femoralis* that vigorously defends its calling territory. We found that territorial males of *E.

Abstract

Animal acoustic signals play seminal roles in mate attraction and regulation of male spacing, maintenance of pairbonds, localization of hosts by parasites, and feeding behavior. Among vertebrate signals, it is becoming clear that no single stereotyped signal feature reliably elicits species-specific behavior, but rather, that a suite of characters is involved. Within the largely nocturnal clade of anuran amphibians, the dart-poison frog, Epipedobates femoralis , is a diurnal species that physically and vigorously defends its calling territory against conspecific intruders. Here we report that physical attacks by a territorial male are provoked only in response to dynamic bimodal stimuli in which the acoustic playback of vocalizations is coupled with vocal sac pulsations, but not by either unimodal cues presented in isolation or static bimodal stimuli. These results suggest that integration of dynamic bimodal cues is necessary to elicit aggression in this species.