Fig. 4. (A) Body pitch, (B) roll and (C) yaw orientation through five wingbeats of a turn. Wingbeats are numbered across the top of the figure, with wingbeat 0 falling at mid-turn. Downstrokes are shaded gray. Solid lines are the data subject to normal processing, i.e. a 37 Hz low-pass filter. Broken lines were processed with a 4 Hz low-pass filter to show only the inter-wingbeat changes in orientation. Note negative pitch is `beak up' in the body coordinate system we used, thus the inverted axis in A.