Olfactory cognition of social relationships in primates

• Applicant: Dr. Brigitte Schlögl
• Subject Area: Sensory and Behavioural Biology
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 431042684

The sense of smell is among the evolutionarily oldest of the animal senses and plays a pivotal role in social cognition and communication in numerous mammals. The importance of olfaction for social life is also well-established in evolutionarily older primate taxa such as lemurs and lorises. Catarrhine primates (Old World monkeys and apes), however, have historically been assumed to rely little on the sense of smell due to their strong visual orientation. Although this notion is increasingly considered outdated, it has resulted in a scarcity of olfactory studies in these taxa. This is vital insofar as catarrhines are considered to be the primates with the most complex social relationships. Managing these relationships poses considerable cognitive challenges, requiring animals to obtain social knowledge about conspecifics and to track their own and others' social interactions over time. As olfactory cues can provide social information that is (temporarily) absent in other sensory domains or enhance the precision and reliability of other sensory cues, they could contribute significantly to managing these intricate relationships. Even so, the recognition of social attributes and relationships in catarrhine primates has been studied primarily in the visual and auditory domain. This severe paucity of studies on the role of olfaction in catarrhine social cognition poses a significant gap in our understanding of primate communication and the evolution of social complexity. The proposed project will therefore assess olfactory cognition of social relationships in Barbary macaques (Macaca sylvanus), an Old World monkey with sophisticated social relationships known to recognize individual attributes and social relationships using visual and auditory cues. We will employ a powerful, integrative approach that combines analysing the chemical composition of Barbary macaque scents with experimental presentations of conspecific scents. To do so, we will use state-of-the art, non-invasive sampling protocols, highly sensitive gas chromatography-mass spectrometry analysis and well-established cognitive test paradigms. In particular, we will determine which basic (identity, kinship, rank) and derived (third-party, group composition) social information can be obtained from the scents of Barbary macaques in two habituated, semi-free ranging populations living in naturalistic social settings. By relating the information contained in the composition of scents to the use of olfactory cues by monkeys for recognizing individual attributes and social relationships, the project will substantially contribute to understanding the olfactory mechanisms and cognitive underpinnings of managing social relationships as well as the evolution of primate communication and social complexity.

• DFG Programme: Research Grants