Supplementary Material from Misinformed leaders lose influence over pigeon flocks

In animal groups where certain individuals have disproportionate influence over collective decisions, the whole group's performance may suffer if these individuals possess inaccurate information. Whether in such situations leaders can be replaced in their roles by better-informed group mates represents an important question in understanding the adaptive consequences of collective decision-making. Here, we use a clock-shifting procedure to predictably manipulate the directional error in navigational information possessed by established leaders within hierarchically structured flocks of homing pigeons (<i>Columba livia</i>). We demonstrate that in the majority of cases when leaders hold inaccurate information they lose their influence over the flock. In these cases, incorrect information is filtered out through the rearrangement of hierarchical positions, preventing errors by former leaders from propagating down the hierarchy. Our study demonstrates that flexible decision-making structures can be valuable in situations where ‘bad’ information is introduced by otherwise influential individuals.