Terminal attack trajectories of peregrine falcons are described by the proportional navigation guidance law of missiles

Significance Renowned as nature’s fastest predators, peregrines are famous for their high-speed stooping and swooping attack behaviors. We used miniature GPS receivers to track peregrines attacking dummy targets thrown by a falconer or towed by a drone and fitted a simulation describing the dynamics of the guidance system used in interception. We collected onboard video giving a falcon’s-eye view of the attacks and used this to validate our conclusions for attacks on live targets. Remarkably, we find that the terminal attack trajectories of peregrines are described by the same feedback law used by visually guided missiles, but with a tuning appropriate to their lower flight speed. Our findings have application to drones designed to remove other drones from protected airspace.