Coordinated Behaviour in Pigeon Flocks
Fig 7
Illustration of the equal radii (a)-(c) and parallel path (d)-(f) turning cases.
Panels show half-circle long trajectories of individuals belonging to idealistic flocks flying on a radius of 30 m. The internal structure of the flock was modelled by distributing 10 individuals evenly along a circle with a radius of 5 m. (a) During E type turning the orientation of the internal structure is fixed to a global coordinate system. The trajectories of individuals draw circles with a common radius as shown in (b). In the flock’s co-moving coordinate system (shown in (c)) the flock is rotating, as indicated by red arrows. The rotation is in the opposite direction compared to the turning, and individuals at front end up at the back of the flock after a half-circle turn. (d) During P type turning the internal structure of the flock is not rotating in the co-moving coordinate system. And individuals fly along concentric circles as shown in (e). In this case, individuals keeps both their longitudinal and lateral relative positions as in (f).