Meeting Abstract
Bats demonstrate a remarkable capacity to recover flight stability after perturbations from the environment. This ability is likely supported by the precisely-timed recruitment of wing muscles, which modulate the production of aerodynamic forces. However, we know little about neuromuscular control mechanisms in bat flight. Studies of limb movement in response to perturbations during terrestrial locomotion show a proximo-distal control gradient in which performance of muscles that control proximal joints is insensitive to perturbations, in contrast to activity of muscles controlling more distal joints. We hypothesized that when flight is asymmetrically perturbed, the activity of left and right pectoralis major muscles would remain synchronized. To test this, we recorded electrical activity of the pectoralis muscles using wireless dataloggers (Vesper Pipistrelle, 4.1g) from five Rousettus aegyptiacus trained to fly along a corridor (1.5 x 6.0 x 2.0m). Bats passed through a window that divided the corridor’s length in half en route to a landing pad; in perturbed flights, a jet of air was delivered to one wing (2.5X body weight) as bats flew through the window. We tracked the 3D position of 15 markers on each individual using six high-speed cameras. We compared the timing of muscle recruitment with kinematics for all flights. Results show symmetrical recruitment in all flight trials, demonstrating that recovery of stable flight after perturbation does not alter the recruitment symmetry of the pectoralis in Rousettus aegyptiacus. This supports the idea that proximo-distal limb muscle activation gradients are a fundamental characteristic of vertebrate neuromechanical control.
