Meeting Abstract

21.2  Thursday, Jan. 3  Gliding Ants: 3D Kinematics, Maneuvers and Behaviors MUNK, Y; Univ. of California, Berkeley yonatanmunk@berkeley.edu

Gliding ants of the genus Cephalotes have been shown to be capable of directed aerial descent in the absence of wings or any other obvious morphological adaptations for aerodynamic performance. The first step towards understanding the mechanisms by which these ants control the aerodynamic forces acting upon them during gliding is to analyze the postures and behaviors employed while falling and executing defined maneuvers. Using paired high speed video cameras, I obtained 3D kinematics for C. atratus ants gliding in the presence of a landing target. Freely falling ants followed spiraling trajectories and were found to be capable of directing their aerial descent towards and subsequently landing upon a target. Using high-speed video, I also recorded the postures assumed by C. atratus ants gliding in a vertical wind tunnel. Ants gliding at steady state adopted a characteristic backwards gliding posture in which the hind legs were raised dorsally and angled posteriorly while the fore and mid legs were outstretched. Aerodynamic maneuvers were correlated with asymmetric bending of the middle and front legs. Landing maneuvers were investigated by propelling the ants at a vertical target and filming the target region with a high speed video camera. In many cases, ants performed corrective maneuvers in both roll and yaw within 50ms of impact so as to land feet-first on the target. A variety of impact postures were observed, but most commonly ants were observed to hit the target area as though they were ‘parallel parking’, with their dorsal surface pointing up parallel and striking with all legs on one side, sometimes catching hold with as few as one leg.