Figure 1.

Changes in angle of attack relative to the masking board. (A) The angle of attack, α, is defined as the angle between the flight trajectory and the plane of the masking board (side view). The masking board was placed either 10 cm or 30 cm behind the platform. The masking board was positioned 90 degrees relative to the average flight path of each bat (top view). (B) Changes in α (degrees) for all bats in the different conditions, n = 6 bats. The whiskers indicate the extreme data points (beyond the percentiles) that are not considered outliers. Asterisks indicate a significant change in angle relative to either the no masker condition (for 30 cm and 10 cm) or to the 30 cm styrofoam condition (for 30 cm foam). (C) Changes in α in the different conditions for the six individual bats (different colors; mean ± SE). The same trend of decrease in angle can be seen in five out of the six bats. The sixth bat (Stevie) showed an initial decrease from no masker to 30 cm and then kept a relatively similar angle. Note that the initial angle in the no masker condition is already low relative to other bats and by decreasing it further in the masker conditions, this bat used the smallest angle in the experiment. The first bat, ‘Alvin’, performed an additional condition of 20 cm that corresponds to a different foam condition of 20 cm foam. This is because this bat did not have the 30 cm foam condition, and so in order to have a proper comparison between the conditions we compared the 20 cm styrofoam to 20 cm foam.