Photogrammetric Reconstruction of Tandem-Wing Kinematics for Free-Flying Dragonflies Undergoing a Range of Flight Maneuvers

Abstract

Photogrammetric methods are used to reconstruct the body and wing kinematics of free-flying dragonflies. A novel experimental setup was designed and constructed to allow for repeated untethered flights in a constrained flight arena. Kinematic data are presented for twelve individual flights and a total of 23 complete wing strokes, including unaccelerating, accelerating, climbing, and turning flight. High variability is observed in the wing motions employed by individual dragonflies, particularly in terms of stroke amplitude, pitch angle, and wingbeat frequency. Forewing and hindwing flapping is found to be neither in phase nor fully out of phase across all cases, with the forewings lagging the hindwings by an average of 90 degrees. Downstroke durations are observed to be shorter than upstroke durations except in highly accelerating flights. Migratory dragonflies are found to exhibit notably different wing kinematics than non-migratory species.