Fig. 3. Timelines of leg and wing events during (A) voluntary (N=16) and (B) escape (N=27) take-offs. Each timeline represents the flight initiation sequence for an individual fly, and the timelines are aligned such that lift-off occurs at 0 ms. Black lines correspond to the duration of wing-opening for left (L; upper black line) and right (R; lower black line) wings. The line starts at the time of first wing movement, and ends when the wing is in its fully raised position. In some cases, the wing had not reached its fully raised position when the wings began stroking, leading to wing bending on the upstroke. Wing bending is represented by a thinner black line, which ends at the time when the wing was successfully unfurled. The grey and white bands represent the periods of upstroke and downstroke, respectively. These bands end when the fly left the field of view of the cameras. The red line shows the period of mesothoracic leg extension. It starts when the legs first begin to move and ends when the legs stop extending, usually at the point of lift-off, shown by the thin vertical red line.