In the mid 1960s, researchers found that murmurating birds, particularly starlings, interact—not always, but often—with six or seven of their closest neighbors, who interact with six or seven of their closest neighbors. In recent years, studies posit that a network with seven neighbors optimizes the trade-off between “group cohesion and individual effort.” One theory among researchers, in the context of predation, is that starlings are “managing uncertainty while maintaining consensus.” – Nautilus