Revelando a comunicação vocal do ratinho-goytacá (Cerradomys goytaca) e sua relação com diferentes traços comportamentais

Abstract

We investigated aspects of acoustic communication and its relationship with behavioural traits in Cerradomys goytaca, a threatened and endemic Neotropical rodent from Brazil. The study involved 27 captive individuals recorded in pairs to address two main objectives: to describe the species’ vocal repertoire and to explore potential associations between bioacoustics parameters and behavioural traits, such as boldness, anxiety, exploration, and activity. For vocal repertoire description, pairings were conducted in different configurations (heterosexual and homosexual dyads, as well as individuals with varying degrees of kinship), whereas for personality analysis, we followed a protocol using heterosexual dyads regardless of kinship. In describing the vocal repertoire, we identified six vocal types spanning a frequency range that included both audible and ultrasonic vocalisations. This finding represents the first record of ultrasonic vocalisations for the Sigmodontinae subfamily. Vocal classes such as “quaver” and “sweep calls” exhibited high classification accuracy, while others, like “squeak,” displayed greater variability and overlap with other vocal classes, suggesting a potentially continuous vocal repertoire. We also observed that the emission of different vocalisation types varied according to pairing contexts, such as the increased use of "quavers" in unrelated male-female interactions. Regarding the relationship between behavioural and acoustic traits, we found significative associations between dominant frequency and call duration with anxiety and boldness. Additionally, vocal repertoire size was associated with behavioural traits such as boldness, exploration, anxiety, and activity. Despite the limitations in drawing inferences about the species’ behaviour and acoustic communication due to the captive setting, this study contributes to understanding a species within a largely understudied group. Overall, this research provides a descriptive and analytical foundation for the acoustic communication of C. goytaca and highlights the potential for integrating behavioural and bioacoustics approaches. The findings underscore the complexity and richness of the species’ vocal repertoire, offering initial insights into its ecological and social significance. Furthermore, the information presented here provides valuable data for utilising bioacoustics in conservation strategies for elusive species like the goytaca-rat.