Wave flight (birds)

The wave or bolt flight , intermittent flight is the way many small and medium-sized birds fly, especially many round-winged songbirds . Phases with rapid wing beats, in which the birds gain height, alternate with pauses in flapping, in which the birds descend like arrows.

Sir Michael James Lighthill gave a simple explanation for this form of bird flight : Whenever the frictional resistance on the extended wings is greater than the lift-dependent induced resistance, energy can be saved - for a given flight path - by the bird temporarily putting on its wings. Of course, birds only have this advantage if their flight speed is significantly higher than the speed with the lowest air resistance (which in turn is slightly above the optimal speed with the lowest possible effort). Only small birds that have relatively large reserves of power can fly intermittently.

literature

• Jeremy MV Rayner, Paolo W. Viscardi, Sally Ward, John R. Speakman: Aerodynamics and Energetics of Intermittent Flight in Birds . In: American Zoologist . tape 41 , no. 2 , 2001, p. 188-204 , doi : 10.1093 / icb / 41.2.188 .