Long-term tracking of social structure in groups of rats

TL;DR

This study used a long-term automated tracking system to analyze the evolution of social hierarchies in groups of rats, revealing the complexity and context-dependence of social behaviors over time.

Contribution

It introduces a novel long-term tracking approach to study social structure dynamics and shows limitations of traditional pairwise tests in predicting group behavior.

Findings

Social hierarchies evolve over 250 days.

Traditional tests poorly predict group behavior.

Social interactions are highly context-dependent.

Abstract

Rodents serve as an important model for examining both individual and collective behavior. Dominance within rodent social structures can determine access to critical resources, such as food and mating opportunities. Yet, many aspects of the intricate interplay between individual behaviors and the resulting group social hierarchy, especially its evolution over time, remain unexplored. In this study, we utilized an automated tracking system that continuously monitored groups of male rats for over 250 days to enable an in-depth analysis of individual behavior and the overarching group dynamic. We describe the evolution of social structures within a group and additionally investigate how past behaviors influence the emergence of new social hierarchies when group composition and experimental area changes. Notably, we find that conventional individual and pairwise tests exhibit a weak correlation with group behavior, highlighting their limited accuracy in predicting behavioral outcomes in a collective context. These results emphasize the context-dependence of social behavior as an emergent property of interactions within a group and highlight the need to measure and quantify social behavior in more naturalistic environments.