Figure 3.

(a) Summary of the terminology used to report notable species roles in mixed flocks. (b) The accumulation of studies that reported these roles over the past 150+ years. The timeline in (b) is annotated with the first published manuscript to mention either sentinel, leader or nuclear behaviour. Note that ‘leader’ is labelled twice here. Even though Bates [13] was the first to mention this behaviour, the local native communities were the ones who communicated this to him, which Bates largely dismissed as a myth. Two additional important works are denoted on the far right, after which species roles have been reported more frequently.