Abstract # 1548 Event # 31:

Scheduled for Monday, June 26, 2006 02:20 PM-02:40 PM: Session 4 (Kama B)

Towards the evolutionary roots of acoustic communication in primates - new insights from nocturnal lemurs

E. Zimmermann
Institute of Zoology and Center of Systems Neuroscience, Hannover, Germany
     Since Darwin it is known that a fundamental trait of the communication system of all mammals is to convey emotions. In the acoustic domain emotions are transmitted by speech and music in man and by non-verbal acoustic communication in all mammals. The acoustic expression of emotions and their recognition are major prerequisites for social contagion, social synchronization and cooperation. The evolutionary basis of this phenomenon is not well understood. We have studied acoustic communication in nocturnal lemurs representing the ancestral primate condition. These lemurs forage solitarily during the night, cache infants temporarily in nests or dense vegetation and form stable groups during the day. We revealed that socially contagious communication sounds are already present in them. Thus, antiphonal calling is used in the context of infant care, group reunion and coordination of group movement, and duetting in the context of territorial defence. Antiphonal calling, duet songs and choruses given under similar circumstances are also widespread in cathemeral and diurnal, permanently cohesive primate groups. These findings support the hypothesis that environmental and behavioural constraints have shaped the evolution of emotional contagiousness in the acoustic communication system of primates.