Inter-leg Coordination and Static Stability of Walking Drosophila in Courtship

Abstract

Animals use different gaits (leg coordination patterns) to move at different speeds. Abundant research examines the step characteristics and leg coordination of walking Drosophila under controlled conditions, where individual flies exhibit straight forward walking. It remains unclear what walking patterns flies choose under a more complex, naturalistic behavior paradigm, such as courtship. During courtship, male flies exhibit a repertoire of walking behaviors, including following, turning, and circling. These behaviors require precise, flexible temporal and spatial coordination of limb movements. Here I explore how male flies position their legs in courtship context. Using high-speed videography and pose estimation, we tracked male Drosophila during engaged (active courtship) and disengaged walking. We found that while stepping kinematics (stance duration and step length) were broadly similar across social contexts, static stability of the leg coordination diverged. Specifically, engaged males exhibited greater use of more stable coordination patterns, particularly at low to intermediate speeds. These findings indicate that while locomotor parameters remain stereotyped, static stability is flexibly modulated during social interactions. We conclude that social goals, such as tracking or signaling to a mate, shape locomotor strategy. This study highlights how internal and external context shape motor output and raises the question of how neural circuits integrate social cues to influence movement in natural behaviors.