Network analysis highlights socio-demographic patterns of stone tool-using primates

Area of Science:

• Primate behavior
• Ethology
• Animal cognition

Background:

• Tool use in primates offers nutritional and social learning benefits.
• Limited understanding exists on the connection between primate tool use and social dynamics.

Purpose of the Study:

• Investigate the social aspects of stone tool use in a hybrid population of long-tailed macaques.
• Examine socio-demographic patterns, including sex and dominance rank, related to tool use.
• Analyze social network structures of tool users versus non-users.

Main Methods:

• Studied a hybrid population of long-tailed macaques (Macaca fascicularis aurea × M. f. fascicularis) on Koram Island, Thailand.
• Collected data on tool use, sex, dominance rank, and social interactions (grooming).
• Employed social network analyses to map associations and connectivity.

Main Results:

• Males were more likely to engage in tool use than females; dominance rank was not correlated with tool use.
• Tool users and non-users exhibited comparable social connectivity, grooming rates, and partner numbers.
• Grooming network analysis revealed non-users preferentially associated with other non-users, while tool users displayed no such affiliative bias.

Conclusions:

• Tool use behavior integrates into primate social systems, especially in populations with diverse technological behaviors.
• Social network analysis provides insights into the integration of tool use within primate social structures.
• Findings highlight nuanced social associations related to tool use in long-tailed macaques.