Reciprocal relationships in collective flights of homing pigeons

TL;DR

This study reveals that collective flight in homing pigeons is governed by a combination of reciprocal interactions and hierarchical leadership, challenging the idea of exclusive leadership or averaging mechanisms.

Contribution

It demonstrates that both reciprocal relationships and stratified leadership are simultaneously essential in pigeon flock dynamics.

Findings

Reciprocal relationships are significant in pigeon flock movement.

Hierarchical leadership coexists with reciprocal interactions.

An integrated model of compromise and leadership explains collective motion.

Abstract

Collective motion of bird flocks can be explained via the hypothesis of many wrongs, and/or, a structured leadership mechanism. In pigeons, previous studies have shown that there is a well-defined hierarchical structure and certain specific individuals occupy more dominant positions --- suggesting that leadership by the few individuals drives the behavior of the collective. Conversely, by analyzing the same data-sets, we uncover a more egalitarian mechanism. We show that both reciprocal relationships and a stratified hierarchical leadership are important and necessary in the collective movements of pigeon flocks. Rather than birds adopting either exclusive averaging or leadership strategies, our experimental results show that it is an integrated combination of both compromise and leadership which drives the group's movement decisions.