Meeting Abstract
Airflow conditions close to the Earth’s surface are often complex, posing challenges to flight stability and control of volant taxa. Maintaining flight while being subjected to aerial disturbances would require efficient sensorimotor system capable of sensing disturbances and effectuating control maneuvers. Hummingbirds are ideal organisms for studying the influence of aerodynamic perturbations on flight, as they forage in a variety of aerial conditions and are powerful flyers. In this study we measured muscle activation of upstroke and downstroke muscles and performed computational fluid dynamics analysis to identify the flight control strategies implemented by hummingbirds when flying in a longitudinal vortex that induced strong roll perturbations. It was noted that the birds maintained significantly asymmetry wing kinematics of either wings. The birds could maintain significantly different bilateral wing kinematics with only small variation in the timing of each muscle. Additionally, the kinematics of each wing remained consistent over many strokes, suggesting that the birds made fixed systematic modifications to their kinematics when subjected to the “steady” aerodynamic roll perturbation. Computational analysis revealed that the birds produced the necessary torque to maintain flight in the vortex, mainly through the bilateral asymmetry in wing angle of attack. Our results highlights the exceptional flight prowess of hummingbirds and their capacity to devise control strategies even in unfamiliar and unique aerial conditions.
