Sophisticated Communication in the Brazilian Torrent Frog Hylodes japi

Abstract

Intraspecific communication in frogs plays an important role in the recognition of conspecifics in general and of potential rivals or mates in particular and therefore with relevant consequences for pre-zygotic reproductive isolation. We investigate intraspecific communication in Hylodes japi, an endemic Brazilian torrent frog with territorial males and an elaborate courtship behavior. We describe its repertoire of acoustic signals as well as one of the most complex repertoires of visual displays known in anurans, including five new visual displays. Previously unknown in frogs, we also describe a bimodal inter-sexual communication system where the female stimulates the male to emit a courtship call. As another novelty for frogs, we show that in addition to choosing which limb to signal with, males choose which of their two vocal sacs will be used for visual signaling. We explain how and why this is accomplished. Control of inflation also provides additional evidence that vocal sac movement and color must be important for visual communication, even while producing sound. Through the current knowledge on visual signaling in Neotropical torrent frogs (i.e. hylodids), we discuss and highlight the behavioral diversity in the family Hylodidae. Our findings indicate that communication in species of Hylodes is undoubtedly more sophisticated than we expected and that visual communication in anurans is more widespread than previously thought. This is especially true in tropical regions, most likely due to the higher number of species and phylogenetic groups and/or to ecological factors, such as higher microhabitat diversity.

How the environment shapes animal signals: a test of the acoustic adaptation hypothesis in frogs

“…However, the rarity of visual communication in the present data set prevents us from drawing conclusions on its impact on call evolution because of the lack of statistical power. It would be worth investigating call evolution in other frogs using bimodal communication during advertisement, such as Micrixalus Boulenger, 1888 or Hylodes Fitzinger, 1826 (Preininger et al, 2013;de S a et al, 2016), and comparing the results with other taxa using bimodal communication to better understand the evolution of multimodal communication in animals (Rosenthal & Ryan, 2000).…”

The vocal sac of Hylodidae (Amphibia, Anura): Phylogenetic and functional implications of a unique morphology

“…Most of the species of Hylodes we examined were reported to have well developed, paired vocal sacs [H. dactylocinus, (Pavan, Narvaes, & Rodrigues, 2001); H. japi (de S a, Canedo, Lyra, & Haddad, 2015;de S a et al, 2016); H. meridionalis (Mertens, 1927); H. otavioi (Sazima & Bokermann, 1982); H. perere (Silva & Benmaman, 2008); H.…”

“…For example, species of Hylodes perform visual displays in their reproductive behavior (Haddad & Giaretta, ; Narvaes & Rodrigues, ; Wogel, Abrunhosa, & Weber, ) as do several other distantly related, diurnal species that mate in noisy environments such as mountain streams (Hödl & Amézquita, ; Krishna & Krishna, ; Preininger, Boeckle, & Hödl, ). In particular, male H. japi perform complex, multimodal displays that involve a wide range of stereotyped movements, perhaps the most exceptional of which is the asymmetric inflation of the vocal sacs (de Sá, Zina, & Haddad, ). Depending on the social context, males can convey information to conspecifics by inflating only one or both of their paired vocal sacs.…”

“…In H. asper and H. phyllodes, vocal sacs are spherical and ventrolateral, whereas in C. schmidti they are kidney-shaped with some dorsal development (i.e., they reach a position posterior to the tympanic membrane). Photos a and b by Vinícius Caldart, c and d by TG stereotyped movements, perhaps the most exceptional of which is the asymmetric inflation of the vocal sacs (de S a, Zina, & Haddad, 2016).…”

Seasonal Reproductive Dynamics of a Lek-Breeding Neotropical Treefrog is not Organized by Male Size (Anura, Hylidae)

“…In anuran species with a lek mating system and a prolonged breeding, males compete and defend resourcebased territories as breeding sites, with disputes occurring mainly via calls, endurance, warning displays, and physical combats (Wells, 1977;Rosa and Andreone, 2012;de Sá et al, 2016;Ospina-L. et al, 2017). Body size is also an important male trait associated with territory defense, thus influencing intrasexual competition.…”