Movie S1 from Evangelista, Ray, Raja and Hedrick, 3D trajectories and network analyses of group behaviour within Chimney Swift flocks during approaches to the roost. Proc R Soc B 10.1098/rspb.2016.2602 from Three-dimensional trajectories and network analyses of group behaviour within chimney swift flocks during approaches to the roost

This movie shows a chimney swift landing flock with the birds highlighted in yellow via background subtraction processing. The flock is engaged in chimney entry and the highlighted bird profiles get larger as they extend their wings and slow down to attempt a landing. Note that this video was selected for its clear sky background and is not from the recording day analyzed here