Vocal complexity and sociality in spotted paca (Cuniculus paca)

Abstract

The evolution of sociality is related to many ecological factors that act on animals as selective forces, thus driving the formation of groups. Group size will depend on the payoffs of group living. The Social Complexity Hypothesis for Communication (SCHC) predicts that increases in group size will be related to increases in the complexity of the communication among individuals. This hypothesis, which was confirmed in some mammal societies, may be useful to trace sociality in the spotted paca (Cuniculus paca), a Neotropical caviomorph rodent reported as solitary. There are, however, sightings of groups in the wild, and farmers easily form groups of spotted paca in captivity. Thus, we aimed to describe the acoustic repertoire of captive spotted paca to test the SCHC and to obtain insights about the sociability of this species. Moreover, we aimed to verify the relationship between group size and acoustic repertoire size of caviomorph rodents, to better understand the evolution of sociality in this taxon. We predicted that spotted paca should display a complex acoustic repertoire, given their social behavior in captivity and group sightings in the wild. We also predicted that in caviomorph species the group size would increase with acoustic repertoire, supporting the SCHC. We performed a Linear Discriminant Analysis (LDA) based on acoustic parameters of the vocalizations recorded. In addition, we applied an independent contrasts approach to investigate sociality in spotted paca following the social complexity hypothesis, independent of phylogeny. Our analysis showed that the spotted paca’s acoustic repertoire contains seven vocal types and one mechanical signal. The broad acoustic repertoire of the spotted paca might have evolved given the species’ ability to live in groups. The relationship between group size and the size of the acoustic repertoires of caviomorph species was confirmed, providing additional support for the SCHC in yet another group of diverse mammals–caviomorph rodents.

Call combination production is linked to the social environment in Western Australian magpies ( Gymnorhina tibicen dorsalis )

“…Thus, it appears that the findings presented in this study indicate a likely functional relationship between social and communicative complexity in magpies. This finding is in line with other studies that indicate intraspecific variation in vocal complexity relates to differences in social group size and composition [26,38,76,77]. To the best of our knowledge, this study is the first to show that the production of call combinations in a lifelong vocal learning species is correlated with social factors.…”

What is simple is actually quite complex: A critical note on terminology in the domain of language and communication.

“…In other words, both human and animal communication systems are seen as more complex if they consist of bigger and/or more heterogeneous signal repertoires. Upon closer scrutiny, however, it appears that despite this convergence on terminology, the two fields somewhat diverge in their conclusions with respect to the effect of social complexity: An increase in animal group size is typically associated with more signal variation (e.g., primates: Dobson, 2009; McComb & Semple, 2005; rodents: Lima et al, 2018; Pollard & Blumstein, 2011; bats: Knörnschild et al, 2020), whereas an increase in human group size is typically associated with less lexical and acoustic variation among speakers (Dachkovsky et al, 2018; Meir & Sandler, 2019; Meir et al, 2012; Raviv et al, 2019; Reali et al, 2018).…”

Self-Domestication Underground? Testing for Social and Morphological Correlates of Animal Personality in Cooperatively-Breeding Ansell’s Mole-Rats (Fukomys anselli)

“…Finally, sophisticated vocal behaviors have been discussed as indicators for self-domestication (Ghazanfar et al, 2020), although they are in fact not apparent in most domestic mammal lineages. Indeed, the vocal communication in Fukomys and other social bathyergids is more elaborate than in other rodents (Bednářová et al, 2013), but this pattern follows a general trend linking increased sociality to greater vocal repertoires in the rodent order (Lima et al, 2018). Vocal communication in African mole-rats is a topic of ongoing research, with particular attention being paid to the naked mole-rat, in which a complex interplay between social variables and vocalizations has been described (Barker et al, 2021).…”