Multicomponent and multisensory communicative acts in orang-utans may serve different functions

Area of Science:

• Primate communication
• Animal behavior
• Multimodal signaling

Background:

• Human communication is inherently multimodal, integrating various sensory and communicative channels from infancy.
• While evidence for multimodal communication exists in nonhuman primates, research often fails to separate signal production from perception.
• The specific functions of integrated articulators (multicomponent acts) and sensory channels (multisensory acts) remain unclear.

Purpose of the Study:

• To investigate the production and perception of multicomponent and multisensory communication in Bornean and Sumatran orang-utans.
• To differentiate the functions of signal production versus perception in primate social interactions.
• To compare communication strategies in wild versus captive orang-utan populations and across different social dyads.

Main Methods:

• Observation of close-range social interactions in wild and captive Bornean and Sumatran orang-utans.
• Analysis of the use of multicomponent (involving multiple articulators) and multisensory (involving multiple sensory channels) communicative acts.
• Comparison of signal production and perception across different social contexts (e.g., mother-infant dyads vs. others) and environments.

Main Results:

• Multicomponent acts were more frequent than unicomponent acts when communicative goals misaligned with expected outcomes, and were more common in non-mother-infant dyads and Sumatran orang-utans.
• Multisensory acts proved more effective than unisensory acts and were utilized more by wild orang-utans compared to captive ones.
• Production and perception of communicative signals showed distinct functional patterns.

Conclusions:

• Multisensory communication primarily serves to enhance the effectiveness of signals.
• Multicomponent communication becomes important in situations with less predictable interaction outcomes.
• Distinguishing between the production and perception of signals is crucial for understanding the nuanced functions of multimodal communication in primates.