Kinematics of diving Atlantic Puffins (Fratercula arctica, L.): Evidence for an active upstroke.
To examine the propulsion mechanism of diving Atlantic puffins (Fratercula arctica), their three-dimensional kinematics was investigated by digital analysis of sequential video images of dorsal and lateral views. During the dives of this wing-propelled bird, the wings are partly folded, with the handwings directed backwards. The wings go through an oscillating motion in which the joint between the
