Meeting Abstract

32.2  Friday, Jan. 4  The 3D kinematics of the trunk and hindlimbs during take-off and landing in zebra finch (Taeniopygia guttata) PROVINI, P*; BIEWENER, A A; ABOURACHID, A; Muséum National d’Histoire Naturelle, Paris; Muséum National d’Histoire Naturelle, Paris; Department of Organismic and Evolutionary Biology, Concord Field Station, Harvard University, Cambridge provini@mnhn.fr

Take-off and landing are crucial components of avian flight but the mechanical aspects of these phases are not well-understood. A previous analysis on the relative contributions of the wings and legs during these two phases has demonstrated the prominent role of the hindlimbs in the propulsion during take-off and deceleration during landing. Moreover, the importance of trunk 3D motion control during differing locomotor behaviors in birds has encouraged us to undertake a kinematic analysis not only of the legs, but also of the trunk during take-off and landing. For that purpose, we used X-ray methods (XROMM) to reconstruct the 3D kinematics of the trunk and the hindlimbs, in zebra finch (Taeniopygia guttata). Our data revealed the existence of two phases in both motions: a rapid phase corresponding to parasagittal and linear motions of the trunk and the femur, and a slower phase corresponding to relatively complex motions of the trunk, with pitching motions in a parasagittal plane. Moreover, during the propulsion associated with take-off, and the energy absorbed during landing, distal parts of the legs seem to play the role of a spring-damper unit, with a high extension or flexion at the ankle and knee, respectively. This kinematic analysis highlights the fundamental role of the hindlimbs and the femur/trunk association during take-off and landing. Our results also demonstrate the existence of different functional modules within the bird’s skeletal system during these two phases of flight.