Fig. 8. Predicted versus estimated inertial change in roll for an entire wingbeat. As in Fig. 6, roll measurement was subjected to a high-pass filter prior to extracting the measurement. Note that this particular regression includes three points (marked by asterisks) that are more than three standard deviations from the mean of at least one of the axes. Removing these points would reduce the r² of the regression to 0.089 and the P value to P=0.02.