Collective behavior in starling flocks and insect swarms
Institute for Complex Systems, CNR, Italy
Collective behavior in biological systems cuts spatial and temporal scales involving organisms that are greatly different: from clusters of bacteria and colonies of cells up to insect swarms, bird flocks, fish school and vertebrate groups. A striking connection with statistical physics clearly stands out, namely the emergence of large-scale patterns from local interactions between the many elements of the system. It is therefore reasonable to describe collective behavior in biology within the same conceptual framework of statistical physics to identify the common traits of collective behavior. In this talk I will present the results obtained in the last years by the CoBBS Group (Rome - Italy) on starling flocks and midge swarms. These two systems display completely different collective behavior, namely coordinate movements in the case of flocks and apparently random movements in the case of swarms, and a different way to interact, namely topological (flocks) vs metric (swarms) interaction. Despite these differences, the analysis of 3D empirical data with classical statistical physics tools reveals that both systems are characterized by strong spatio-temporal correlation functions and they both shows evidence of scaling laws. Therefore strong spatio-temporal correlations and scaling seem to be the very hallmark of collective behavior.