September 2022
Bird of the Month
Ryan Crouse

Peregrine Falcon

In the animal world, some species elicit a certain awe. Very often these are the apex predators that sit atop the food chain. The lions on the Serengeti, wolves in the Yukon and the great white sharks patrolling our oceans are examples of creatures held in a reverence reserved for the few.

Giant eyes and netlike, taloned feet make the peregrine falcon a capable hunter. Photo by Ryan Crouse

In the bird world this label can apply to any number of species, but the peregrine falcon demands a high spot on that list. They’re cunning hunters that use fantastic speed and laser precision to incapacitate their prey before they ever know what hit them. As you may know, they are the fastest creatures on earth. In a dive they can reach speeds in excess of 200mph; the fastest recorded peregrine was an individual named Frightful, who in 1999 clocked an eye-watering 242mph, a feat that manned flight did not achieve until 1922.

The entire hunt is a carefully choreographed and timed aerobatic display that we have only recently been able to imitate. Many of the most fundamental concepts that make manned flight possible were observed and copied from what we see in nature.

Take this bird’s incredible eyesight, roughly eight times more powerful than ours, and compare it to the complex avionics we carry aboard modern aircraft. Both systems are used to survey upcoming airspace for hazards, navigate at high rates of speed and acquire and close on targets with high accuracy. The peregrine preys on other birds almost exclusively, and can lock on a target from over three kilometers away — nearly two miles!

Once locked on, the falcon begins her dive from a soaring position, much the way a military aircraft loiters over a target, or from a high perch, such as a cliff face or high-tension electrical tower.

While capable of exceeding the magical 200mph barrier, it more commonly performs its dive (‘stoop’) in the 100-150mph range. It tucks back its angular wings, making them as “slippery” as possible as its cigarlike shape barrels toward the unwary prey.

Its profile is almost copied in the US Air Force’s most advanced stealth bomber, the B2 Spirit. This was not accidental.

The falcon’s large eyes continue to track as the head remains fixed on the target, aided by delicate input from the neck muscles. The nostrils are shaped to redirect the severe shock wave of the 200mph dive, protecting the lungs from those high pressures. The air intakes of our fastest aircraft mimic this principle, protecting the complex jet engines from the immense forces funneled in.

Like a wire-guided missile, the falcon makes minute adjustments based on input from the eyes, right up to the point where it’s on top of the unlucky quarry. With balled-up feet it delivers a blow to the target, instantly incapacitating the bird before streaking past. Then it hits the brakes and twists in a maneuver that can exert a 25-g force on the body.

For you non-fighter pilots, one-g is equal to the force of gravity, what we experience daily. You actually experience mildly elevated lateral g-force any time you drive your car. Next time you turn your steering wheel, let the centripetal force push your body off center. This is the concept, although you’re unlikely to experience even a single g of lateral force that way. To feel even a modest 6-g in a car, you have to be in a Formula 1 race car moving at over 150mph.

Turning back to our falcon, compare its 25-g to its USAF namesake, the F-16 Fighting Falcon, which can maintain around 9-g. Much more than that and the highly trained human inside risks blacking out from blood loss to the brain, or worse, the incredible force can rip the aircraft apart at the seams. The peregrine falcon withstands three times that before breakfast is served.

The predator performs this feat to position itself back on the target, where it can now snare its stricken prey with its oversized, taloned feet. If it finds the animal still alive, it can use what is known as a modified tooth on its upper mandible to reach down and sever the spinal cord, ending the struggle instantly. This tool is one feature that sets falcons apart from other birds of prey.

All that said, the peregrine’s attack-success rate is only 9.3%, which means it has to go through this entire set of events nine or ten times on average before enjoying a meal! Take that into account the next time the grocery store is out of your favorite potato chip.

Until next time, happy birding!

The Prescott Audubon Society is an official chapter of the National Audubon Society. Check it out online at