Long-term tracking of social structure in groups of rats

Abstract

AbstractRodents 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 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 investigate how past behaviors influence the emergence of new social hierarchies when group composition changes. Notably, a comparison of behavior in groups to conventional individual and pairwise behavioral assays reveals that the latter are insufficient for capturing or predicting genuine 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.Author summaryDespite the fact that rodents are a model system for studying both individual and social behavior, testing methods are typically limited to short-term and simple behavioral tests. As a result, it is uncertain how different behavioral patterns interact to create a group’s overall social structure. Using long-term experiments of over 250 days, we employed automated tracking to study rats’ social behavior. We describe distinct aspects of a group’s social structure by employing different quantitative metrics. These methods allowed us to compare group behavior with traditional individual and pairwise behavioral tests. The results indicate that simplified assays do not accurately describe or predict actual behavioral outcomes in a group setting, and emphasize the need to measure and quantify behavior in naturalistic settings with long-term tracking in order to understand group social structure and behavior. Our research establishes a framework for characterizing the social structure of rats and other social animals.