Description of ActivitySpeaker on the 'Use of NetFACS to describe the repertoire of Barbary macaques' facial behaviour.'
Facial signals are important social communication tools in primates that allow them to navigate their social world. Analyses of the complexity of coordinated movements of facial muscles, reflected by the quantity and quality of their relationships, are necessary to apprehend the face as a communication system and investigate the evolution of communication. Macaques facial movements are often classified in broad categories and not systematically described in a standardized way. This subjective clustering prevents us from exploring the subtleties of the morphology of facial displays. The Macaque Facial Action Coding System (MaqFACS) is an anatomically based objective tool used to describe facial behaviour. FACS datasets have features that make traditional statistical models unsuitable for reliable analyses. Network science is one way to overcome these issues. NetFACS is a statistical package combining FACS and network analysis, where the face is conceptualised as a network of interconnected Action Units (AU: the smallest unit of facial communication). AUs are represented as nodes, their combinations as edges that can be weighted to indicate their strength, all visualized in graphs. We coded over 1700 videos of interactions in 46 Barbary macaques (Macaca sylvanus). We used MaqFACS to report variability, diversity and subtlety to provide a fine-grained repertoire of Barbary macaques’ facial behaviour, and NetFACS to define and quantify the communicative complexity of the signals. We found that signals produced in affiliative contexts were more complex, with more AUs involved and more connected, resulting in a denser network. Our results also show that aggressive faces are more predictable than others. Finally, we report the difference of repertoire between males and females across and within contexts.
|3 Jun 2022
|Joint Conference of the European Federation for Primatology and the Gesellschaft fur Primatologie
|Degree of Recognition