Combined effects of body posture and three-dimensional wing shape enable efficient gliding in flying lizards

Gliding animals change their body shape and posture while producing and modulating aerodynamic forces during flight. However, the combined effect of these different factors on aerodynamic force production, and ultimately the animal's gliding ability, remains uncertain. Here, we quantified the time-varying morphology and aerodynamics of complete, voluntary glides performed by a population of wild gliding lizards (Draco dussumieri) in a seven-camera motion capture arena constructed in their natural environment. Our findings, in conjunction with previous airfoil models, highlight how three-dimensional (3D) wing shape including camber, planform, and aspect ratio enables gliding flight and effective aerodynamic performance by the lizard up to and over an angle of attack (AoA) of 55 degrees without catastrophic loss of lift. Furthermore, the lizards maintained a near maximal lift-to-drag ratio throughout their mid-glide by changing body pitch to control AoA, while simultaneously modulating airfoil camber to alter the magnitude of aerodynamic forces. This strategy allows an optimal aerodynamic configuration for horizontal transport while ensuring adaptability to real-world flight conditions and behavioral requirements. Overall, we empirically show that the aerodynamics of biological airfoils coupled with the animal's ability to control posture and their 3D wing shape enable efficient gliding and adaptive flight control in the natural habitat.

Automated summary

Gliding animals can change their body shape and posture to produce and control aerodynamic forces during flight. This study focused on the gliding lizards and found that their three-dimensional wing shape, along with strategies of changing body pitch and modifying airfoil camber, enables efficient gliding and adaptive flight control even at high angles of attack. This allows the lizards to maintain optimal aerodynamic performance and adapt to real-world flight conditions.