La funzione comunicativa delle espressioni facciali e delle attività di sostituzione nel cane domestico

This thesis investigates the nature and functions of visual behavioural patterns exhibited by domestic dogs (Canis lupus familiaris), with a specific focus on displacement behaviours and facial expressions. The first part of the work scrutinizes existing studies on domestic dogs’ displacement behaviours and facial expressions, elucidating their association with physiological indicators of stress, their role as indicators of positive and negative emotions, and their communicative function during social interactions. The experimental inquiries explore domestic dogs’ behavioural and hormonal responses to experimentally induced states of positive anticipation and frustration, with the presence or absence of an intra and interspecific social partner (audience effect). Cortisol levels associated with some displacement behaviours hint at a connection with negative valence arousal, while the presence of an audience generally modulated the behavioural patterns, suggesting a communicative function. Furthermore, different audience types (conspecifics or human partners) influenced the characteristics of the displays exhibited, confirming that this putative communicative signals could be shaped by natural selection based on the characteristics of the receivers. Further investigation evaluates the appeasement signals hypothesis of displacement behaviours, examining their role in mitigating potentially aggressive encounters. Findings suggest that putative appeasement signals are associated with a non-aggressive attitude in the sender but are not exclusive of a conflict ridden context. Finally, the research also explores the use of video stimuli in studying intraspecific dog communication, demonstrating dogs’ ability to respond with socially appropriate behaviours to videos of conspecifics performing different communicative signals. Displacement behaviours are accentuated in response to neutral conspecifics, underscoring their link with potentially ambiguous social contexts rather than overt threat. In conclusion, this research enhances our understanding of domestic dogs’ communication by elucidating the intricate interplay between displacement behaviours, facial expressions, and emotional states. The findings underscore the important role of social context and audience presence in shaping communicative signals, providing valuable insights into the complex dynamics of canine communication. This comprehensive exploration opens avenues for further research into the evolutionary underpinnings and functional significance of canine behavioural displays in diverse social contexts.