Fig. 1. Lateral projection of the wing movements relative to the ground of Glossophaga soricina flying from right to left at slow flight speeds, 2.4-3.5 m s^-1. The top flight shows the tracks of the wingtip of the bat and the other two flights also include the tracks of the thumb. In slow flight (top flight) the wings are moved backwards relative to the ground during the upstroke. As speed increases the wingtip path becomes more vertical. Wing beat frequency (wb s^-1) decreases with increasing flight speed. The times indicated to the left, 0.0055-0.0072 s, are the times between each dot (numbered on the traces). Scale bars, 5 cm.