Correlations of the Position of Center of Body Mass With Butterfly Escape Tactics

Using the evolution of neotropical butterflies as a natural experiment, we examine Ellington's biomechanical hypothesis that the position of center of body mass affects insect maneuverability. We find that the position of center of body mass is correlated with the butterflies' palatability, natural flight speeds and their ability to evade predators in a small cage. Relative to distasteful species, palatable butterflies fly faster and maneuver more successfully to evade attacks from aerial predators. The large thorax and short abdomen of palatable species position the center of body mass near to the wing base, whereas the mass allocation and body shape of distasteful butterflies position center of body mass further posteriorly. The position of center of body mass is an important indicator of flight performance, including both aerial maneuverability and flight speed, that warrants incorporation into future studies of invertebrate and vertebrate flight.