Peregrine falcons are known to be one of nature’s fastest predators, capable of diving through the air at speeds of up to 200 mph.

Their impressive speed, “swooping” moves and accuracy in latching onto their prey mid-air has piqued the interest of researchers for decades. Until now, it was thought that peregrines’ aerial hunting method followed simple geometric rules, but a new study from Oxford University researchers now debunks that theory.

The study results, published recently in PNAS, show that peregrine falcons actually use the same guidance law that missile engineers have developed to guide missiles to moving targets. The findings could be applied to the design of small, visually guided drones that take down other “rogue” drones in no-fly zones, according to the researchers.

Caroline Brighton, Adrian Thomas and Graham Taylor, all from the University of Oxford’s Department of Zoology, spent four field seasons flying a group of eight captive falcons in the Welsh hills. They tracked the birds’ flights with miniature GPS units and observed them during 61 hunting flights – 26 of which used dummy targets thrown by a falconer, and the other 35 were done through drones that had a spinning birdlike lure attached to them.

The team was able to apply a mathematical simulation to the falcons’ movements describing the dynamics of the guidance system used in intercepting the dummy prey.

They also gathered first-hand views of the hunting attacks by attaching small cameras to the backs of the falcons. The video footage validated the team’s conclusions for attacks on live targets.

The researchers discovered that the attack trajectories are described by the same feedback law used by visually guided missiles – known as proportional navigation (PN) – but with a tuning optimized for their lower flight speed. Using PN, falcons can successfully collide with prey by tracking how the pathway between the falcon and the prey target is changing, rather than calculating the speed and direction of both the falcon and its prey.

“Our results from peregrines point to the fact that PN guidance optimized for low flight speeds could find use in small visually guided drones designed to remove other drones from protected airspace,” wrote the study authors.

As the popularity of drones continues to grow among consumers, there have been increasing reports of issues with the devices being used to fly drugs, mobile phones and other contraband into prisons, as well as being flown too close to airports and other no-fly settings.

Peregrine falcons are the first aerial predators for which a guidance law has been formally identified, but the researchers believe that other animals such as dragonflies and robber flies may also use PN for navigation.

The research was funded by the U.S. Air Force Research Laboratory.