Fig. 8. Aerodynamic torques measured on a full-scale physical model of Polypedates dennysi posed in the gliding posture observed during non-maneuvering gliding. Aerodynamic torques about the pitch (A), roll (B) and yaw (C) axes are shown plotted against angle of attack, roll angle and yaw angle, respectively. Lines shown on each graph are linear regressions of the data. The linear regressions of rolling and yawing torque are taken over smaller ranges of roll angle and yaw angle, respectively, than the linear regression for pitching torque; the smaller range of angles reflects the lower level of perturbations in roll and yaw angle during gliding and is consistent with aeronautical engineering practice (McCormick, 1976). (D) Summary of aerodynamic stability coefficients (see text for definitions of coefficients) about the pitch, yaw and roll axes. Stability about a given axis is denoted by negative values, and instability is denoted by positive values. At the gliding speed (13 m s^-1) and angle of attack (45°) used by P. dennysi, the frogs are slightly stable about the pitch axis and roll axes, and slightly unstable about the yaw axis.