Fig. 6. Saccades play a role in the active behavioral response. Saccades were quantified as turns with magnitudes greater than 15° and angular velocities exceeding 300° s^–1. (A) An orientation trace from a fly orienting in a 0.6 m s^–1 wind manifests two rapid turns. (B) An angular velocity trace of the same data as in A, illustrating the spikes in angular velocity that characterize saccades. (C) In live flies, spontaneous saccades (i.e. those exhibited in the absence of wind) were distributed throughout the trial (note that the histograms are stacked). Furthermore, those that improved the flies' orientation relative to upwind (blue bars) did not predominate compared with those that turned the flies away from upwind (red bars). In the presence of wind, saccades tended to cluster near the onset of the wind stimulus and also tended to improve the orientation relative to upwind. In dead flies, saccades were very rare under all conditions.