Supplementary Video from Conversion efficiency of flight power is low, but increases with flight speed in the migratory bat Pipistrellus nathusii

Supplementary Video S1. Schematic video representation of P. nathusii flying in a wind tunnel. Top panel shows the side view of an individual, bottom panel shows an example of the vortex structures of the wake generated by a bat in flight from the rear. The downstroke generates thrust and weight support, while the upstroke wake shows the bat-characteristic inverse vortex rings indicative of negative weight support and thrust production. NB. the same bat is not depicted in both videos.