Two intermittent flight strategies in birds, bounding flight adaptation in birds pdf undulating, are compared. Mechanical energy does not flow steadily from the bird to its environment, but is stored temporarily in the bird’s body in the form of kinetic or potential energy. A simple mathematical model of flight performance is used to show that undulating flight reduces energy at most flight speeds and permits a bird to fly slowly most economically, but that bounding saves energy only at very high speeds, and does not reduce the mechanical cost of transport.
This conclusion is inconsistent with extensive behavioural observations of bounding in migration, and in slow flight and hovering. The use of undulating flight may be dictated by similar considerations. Both modes have evolved as compromise adaptations between the strenuous and conflicting constraints imposed by physiology and mechanics on flying birds. Bounding in birds has been accompanied by reduction in size and widening of adaptability to trophic conditions, while undulating permits larger birds to accommodate the power economy of gliding with efficient flapping flight. Check if you have access through your login credentials or your institution.
1985 Published by Elsevier Ltd. Studies of medium- and large-bodied avian species have suggested that variation in flight muscle composition is related to differences in flight behavior. However, we know comparatively little about fiber composition of the muscles of the smallest birds. These unique results suggest that fast oxidative fibers are both necessary and sufficient for the full range of flight behaviors in these small-bodied birds. We further hypothesize that thermogenic requirements constrain fiber type heterogeneity in these small endothermic vertebrates. This process takes place over many generations.