Fig. 2. Bird outlines drawn from video of a typical jump sequence. Time (ms) is relative to the beginning of the jump, defined as when the vertical acceleration became positive. (1) Bird standing upright. (2) Bird lowering itself into a deep pre-jump crouch. (3) Jump start – point of deepest crouch and start of first upward movement when acceleration becomes positive. (4) Beginning of wing upstroke. (5) Middle of wing upstroke. 6) Start of downstroke. (7) Lift-off.