BISHOP, K.L.; Brown University: Kinematics of short glides in the Southern Flying Squirrel, Glaucomys volans

Gliding flight is of special interest to those who study animal locomotion both because it is a possible precursor to powered flight and because it appears to be an energetically cheap mode of transport. Before we can meaningfully address questions about whether the gliding to flapping transition is a plausible evolutionary scenario in bats, we need to better understand the aerodynamics of living gliding mammals. Thus, it is important to know the range of gliding performance attained by living mammalian gliders and how the details of morphology and kinematics determine performance. Depending on the goal of the gliding behavior, performance parameters of interest could include glide angle (getting as far as possible from a given height), speed, and control of glide trajectory. The goal of this study is to describe the body position and performance of mammals gliding over short distances and to identify correlates between kinematic behavior and aerodynamic performance and to determine which performance parameters (glide angle, speed, and stability) are more or less sensitive to kinematic variation. In the present study, captive Southern Flying Squirrels, Glaucomys volans, were trained to glide short distances in a controlled laboratory setting. Three dimensional kinematics were captured using two high speed video cameras (250 Hz). Reflective markers were positioned on the wrist, ankle, sternum, pelvis, and at the midpoint of the patagium, which allowed measurement of the camber, angle of attack, limb position, glide angle and speed. Results suggest that glide angle and speed are not maximized by the squirrels in short glides and that stability and control are likely to be important.