Vocal complexity and sociality in spotted paca (Cuniculus paca)

Area of Science:

• Ethology
• Bioacoustics
• Evolutionary Biology

Background:

• Sociality in animals is driven by ecological factors and group living payoffs.
• The Social Complexity Hypothesis for Communication (SCHC) posits a link between group size and communication complexity.
• Spotted pacas (Cuniculus paca), though often solitary, show social behavior in captivity and wild group sightings.

Purpose of the Study:

• To describe the acoustic repertoire of captive spotted pacas.
• To test the SCHC in spotted pacas and understand their sociability.
• To investigate the relationship between group size and acoustic repertoire size in caviomorph rodents.

Main Methods:

• Recording and acoustic analysis of vocalizations from captive spotted pacas.
• Linear Discriminant Analysis (LDA) on acoustic parameters.
• Independent contrasts approach to analyze sociality independent of phylogeny.

Main Results:

• The spotted paca possesses an acoustic repertoire of seven vocal types and one mechanical signal.
• A broad acoustic repertoire in spotted pacas may indicate an evolved capacity for group living.
• A significant positive correlation was confirmed between group size and acoustic repertoire size in caviomorph species.

Conclusions:

• The findings support the Social Complexity Hypothesis for Communication (SCHC) in caviomorph rodents.
• Spotted pacas demonstrate a complex communication system potentially linked to their social behavior.
• This study contributes to understanding the evolution of sociality and communication in mammals.