Wild western lowland gorillas signal selectively using odor

Area of Science:

• Primate communication
• Olfactory signaling
• Behavioral ecology

Background:

• Mammals utilize visual, auditory, and chemical signals for social communication.
• Olfactory communication is ancient and widespread, yet its role in wild ape social signaling is understudied.
• Comparative models, particularly among hominoids, can illuminate human social chemo-signaling.

Purpose of the Study:

• To investigate olfactory signaling in wild western lowland gorillas (Gorilla gorilla gorilla).
• To analyze the relationship between odor strength, arousal levels, and social context in wild apes.
• To determine factors predicting extreme silverback odor emission.

Main Methods:

• Observational study of a wild western lowland gorilla group.
• Quantification of silverback odor strength using a human pungency scale.
• Analysis of behavioral and auditory cues associated with odor emission, including inter-unit interactions and vocalizations.

Main Results:

• Extreme silverback odor was linked to inter-unit interactions, anger, distress, and specific social proximity dynamics.
• Odor strength varied based on the silverback's strategic responses during intense social encounters.
• Gorilla scent functions as a context-specific and modifiable communication mechanism.

Conclusions:

• Wild gorillas employ odor as a flexible signaling system, adapting its emission based on social relationships and environmental factors.
• Olfaction plays a crucial role in gorilla social communication, potentially enhanced by limited visibility in forest environments.
• This study provides novel insights into chemo-communication in wild apes, highlighting the adaptive significance of olfactory signals.