Summary: tion may lead to new research into the neuro-
muscular control of aerial maneuvers in ani-
mals (3, 4) and will aid efforts to engineer
controllers and actuators that effect wing
movement in biometic flying robots (10).
Passive stability during flapping may thus be
analogous to a process in terrestrial locomo-
tion in which neural input and passive dynam-
ics interact to augment stability (11).
A major goal of functional morphology
and comparative biomechanics is to under-
stand how animal design relates to movement,
ecology, and behavior. Thus, it is also impor-
tant that Hedrick et al. show that animals with
wings that are large relative to their body size
decrease yaw velocity more quickly than
animals with proportionally small wings.
Hypotheses about maneuverability and eco-
morphology in birds and bats have been dom-
inated by the assumptions of fixed-wing, glid-