Teeth Baring as a Model to Understand Complex Facial Signals in a Tolerant Macaque Species.

ABSTRACT: Facial communication regulates many aspects of social life in human and nonhuman primates. Empirically identifying distinct facial expressions and their underlying functions can help illuminate the evolution of species' communicative complexity. We focused on bared-teeth faces (BTFs), a highly versatile facial expression in the tolerant macaque Macaca tonkeana. By employing a diverse array of techniques (MaqFACS, unsupervised cluster analysis, Levenshtein distance, NetFACS), we quantitatively discriminated two distinct BTFs: bared-teeth (BT) and open mouth bared-teeth (OMBT), and evaluated their distribution across peaceful, playful, and agonistic contexts. Neither BT nor OMBT were context-specific, although BT frequently occurred during peaceful interactions and with low levels of stereot

SUBMITTER: Fantoni F 

PROVIDER: S-EPMC11650955 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature