Communication across multiple sensory modes: quantifying the rich behavioural repertoire of a Neotropical torrent frog

Abstract

Abstract Anuran communication involves different channels of signal transmission, including acoustic, chemical, seismic, tactile, and visual stimuli. If emitted in combination, the components of the different channels form the multimodal communication, which can be important to reinforce, complement, or transfer fundamental information. This is especially key for species that dwell in noisy environments, such as Hylodes phyllodes. This rheophilic frog species has a complex behavioural repertoire, including acoustic and visual signals. In this study, we quantified and characterized the multimodal communication of this species. We identified and characterized advertisement, territorial, and encounter calls. Additionally, we compared the advertisement calls from the same males when emitted with one or both vocal sacs expanded and found that they differed in temporal and spectral parameters. Hylodes phyllodes performed 16 visual displays, which varied among individuals and populations. We elucidate that visual signalling is easily quantifiable and could be used to compare individuals, populations, and species, as typically done with anuran acoustic signals.