The communicative life of a social carnivore: acoustic repertoire of the ring-tailed coati (Nasua nasua)

Abstract

The coati is a highly social mammal that features sophisticated cognitive and social abilities. We hypothesized that the ring-tailed coati, Nasua nasua, uses an extensive acoustic repertoire that correlates to their diverse range of social interactions. We tested this hypothesis by observing and recording a free-ranging managed population of N. nasua in Tietê Ecological Park (PET), in the municipality of São Paulo, State of São Paulo, Brazil. Of 404 h of sampling, 47 h of coati vocalizations were recorded over 3 years. Additional records were obtained opportunistically on other free-living populations at PET by using passive acoustic monitoring. We describe here an acoustic repertoire composed of 15 calls (12 basic calls, 2 rhythmic calls and the non-random complex calls composed of three or four different units). This diverse repertoire of signals was used in contact/cohesion regulation, foraging activities, alert or potential threat situations, playing and fighting interactions and during social isolation and acute distress. The contact call (chirp) is produced through biphonation, and other non-linear phenomena are present. Our study found a complex vocal repertoire that encourages further studies to describe the evolution of the cognitive characteristics and social abilities of ring-tailed coatis.

Keywords:

• Acoustic repertoire
• chirp
• non-linear effects
• procyonids
• vocal complexity
• acoustic complex sequences

Acknowledgements

We thank Drs. Rogério Grassetto, Beatriz Beisiegel, Lílian Ricz, Leandro Magrini and Wagner F. Santos, for reviewing different versions of this manuscript, and also Drs. Elizabeth Costa and L. Magrini for their donation of recordings from populations of PROSA and PARNASO that were helpful to enrich the broad communicative aspects of the ring-tailed coatis. Many thanks as well to the Tietê Ecological Park and Cantareira State Park staff for being supportive throughout the whole study. Finally, we also want to thank Dr. Ilya A. Volodin from the Lomonosov Moscow State University and Dr. Elena V. Volodina from Moscow Zoo for their generous analysis of the non-linear phenomena of the chirp call-types in response to our request.