Abstract: Birds are diverse and agile vertebrates best known for their agility in flight, yet ground birds have a long evolutionary legacy as agile terrestrial bipeds. In the Neuromechancis lab, we use ground birds as animal models to study the integration of mechanics and sensorimotor control for agile bipedal locomotion. Study of avian bipedalism provides opportunities to reveal principles of scaling of gait dynamics with body size, relationships between morphology and neuromechanical function, and the multiple solutions to the fundamental challenge of sensorimotor delay for stable and agile movement. We also collaborate with engineers to enable integrative approaches to understanding animal locomotion, and to apply insights from animal locomotion to biologically inspired robots. Legged locomotion involves abrupt transitions in load between the swing and stance phases and requires precise control of leg-substrate interactions to provide body weight support, maintain stability and avoid injury in varied terrain. In this seminar I will highlight findings from experimental biomechanics and in vivo muscle function that reveal how bipedal animals make effective use of compliance, damping, and postural stability mechanisms to achieve robustly stable and agile performance. I will also discuss how our experimental findings from ground birds have been tested in BirdBot as a physical model of avian bipedal locomotion.