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Physics-based simulations of aerial attacks by peregrine falcons reveal that stooping at high speed maximizes catch success against agile prey

Fig 7

(a) Look-up table for the accelerations due to the aerodynamic forces acting on the falcon. At each model time-step, the falcon maximizes forward acceleration (minimizes deceleration), given its forward speed and with the constraint that load factor is set to achieve the net commanded acceleration by the guidance law. If this constraint cannot be met (i.e. if it is unfeasible due to aerodynamics or high resulting torque forces), the closest approximation of the load factor is chosen. In the blade-element model, the falcon optimizes the wing twist, the wing’s angle-of-attack, the wingbeat frequency and the wing retraction. Inside the trapezoidal contour, the falcon flaps at maximal wingbeat frequency, and outside it the falcon glides. Above the contour, flapping results in too high torque forces on the wing. Gravity is excluded from the accelerations in the figure. (b) The partial derivative of forward aerodynamic acceleration with respect to load factor, termed the “aerodynamic deceleration penalty”.

Fig 7

doi: https://doi.org/10.1371/journal.pcbi.1006044.g007