Meeting Abstract
Pursuit and interception are common behaviors that engage many aspects of locomotor biomechanics, sensory physiology and neural processing. Dragonflies are a well-studied system for prey interception, with a number of different studies examining response latencies and interception algorithms from sit-and-wait species in controlled environments. However, dragonflies also engage in intra and interspecific interactions as part of mating and territory defense and the dynamics of these interactions are less well known. We use a newly developed camera-based mobile 3D videography system to record chases and interactions of several dragonfly species including Libellula luctuosa, Libellula vibrans, and Perithemis tenera in natural environments near Chapel Hill, NC. From the resulting trajectories we quantified the response dynamics, hypothesizing that the interception or tracking algorithms match those used for prey species, but that response latencies would tend to be larger to reduce the possibility of deceptive maneuvers by a target with near-equivalent flight performance capabilities to the pursuer, consistent with analysis of intraspecific chases in barn swallows. Contrary to these expectations, preliminary results show that response latencies based on whole animal trajectories were ~17 ms, less than the ~33 ms reported for predatory tracking and interception, albeit in a different dragonfly species studied in an enclosed environment. Trajectory kinematics were consistent with pursuit and constant bearing tracking, with shifts to a new constant each time the pursued dragonfly made an evasive maneuver and was re-detected by the pursuer. Flight speeds exceeded 8 m s-1, and centripetal forces exceeded 5 body weights.
