The acoustic repertoire of Cavia intermedia as a contribution to the understanding of the Caviidae communication system

Abstract

Wild cavies from the taxon Cavia aperea–Cavia porcellus are known for their extensive use of acoustic signals for communication including a courtship call that is a rarity in Mammalia. The genus Cavia includes an insular species (Cavia intermedia) derived from a continental “asocial” Cavia magna. We hypothesized that the courtship call and all the other 12 acoustic signals previously described for C. aperea–C. porcellus were synapomorphies of the genus and took the opportunity of recording the critically endangered C. intermedia. Four field trips lasting 10 days were conducted in 2008 and 2009. After collecting and analysing nearly 350 sound files of 38 individuals, we found all the 12 calls of wild and domestic cavies previously described, including the courtship call, and a new call, a peep. Despite the presence of the peep, our description of C. intermedia acoustic repertoire showed the evolutionary stability of the acoustic repertoire of this rodent genus of 6 species, even after domestication of C. porcellus and 8000 years under insular selective forces in C. intermedia. We present a discussion about the communicative function of Cavia calls in a comparative context and its repertoire size in accordance with the complexity level of sociality of this caviomorph rodent.

Keywords:

• Alarm whistle
• courtship call
• Hystricognathi
• insular effect
• peep
• Rodentia
• social behaviour
• wild cavy

Acknowledgements

We thank César Ades (in memorian) and Nina Furnari for the opportunity to visit and stay with them in the island, for the theoretical discussions and even for the help in data collection. We are also grateful to Rita Carolina R. B. Tarallo, Raimundo Novaes de Alencar Junior and PhD Dilmar Alberto Gonçalves de Oliveira for their help during recordings. And finally, we thank Professor Fernando Frei for statistical advices and Cintia Tomoe Suzuki, that after describing the acoustic repertoire of free-living capybaras, improved our discussion about caviomorphs acoustic repertoires.