Collective Motion and Decision-Making in Animal Groups

A fundamental problem in a wide range of biological disciplines is understanding how functional complexity at a macroscopic scale (such as the functioning of a biological tissue) results from the actions and interactions among the individual components (such as the cells forming the tissue). Animal groups such as bird flocks, fish schools and insect swarms frequently exhibit complex and coordinated collective behaviors and present unrivalled opportunities to link the behavior of individuals with the functioning and efficiency of dynamic group-level properties.

Using an integrated experimental and theoretical approach involving both insects and vertebrates I will address both how, and why, animals coordinate behavior. In some animal groups decision-making by individuals is so integrated that it has been associated with the concept of a “collective mind”. Since each organism has relatively local sensing ability, coordinated animal groups have evolved collective strategies that allow individuals to access higher-order computational abilities at the group level. I investigate the coupling between spatial and information dynamics in swarms, flocks, schools and herds and reveal the critical role uninformed individuals (those who have no information about the feature upon which a collective decision is being made) play in effective consensus decision-making.

Understanding the information-processing dynamics in groups offers new insight into the evolution of collective behavior. I will explore the relationship between collective behavior and game theoretic dynamics using a framework that is generally applicable to situations where information can be considered a public good. Finally, to better understand how and why grouping has evolved among unrelated individuals, a new experiment will be discussed in which real predators are used to exert selection pressure on virtual prey populations, allowing us to explore both the within-group and between-group selection pressures that influence the evolution of functional collective behaviour. Our results provide insights into both the proximate and ultimate factors that underlie evolved collective behavior.