How do peregrine falcons fly so fast?

Key Takeaways

Peregrine falcons can fly at speeds between 40 and 60 mph (64 to 97 km/h) during normal flight, but can reach over 200 mph (322 km/h) in a hunting dive.
Their speed is due to powerful flight muscles, a large keel, pointed wings with stiff feathers, and efficient cardiovascular and respiratory systems.
Living in high-altitude habitats like cliffs and tall buildings helps them gain speed during their dives.

Walking down a New York City street, the last thing you might expect is for a torpedo to come barreling down at you from atop the Empire State Building. Yet as you absentmindedly watch the pigeons peck away at someone's discarded tuna on rye, an oncoming streak of gray and white barely gives you enough time to take cover under a nearby bench. The pecking pigeons aren't so lucky, and the torpedo, which now appears to have a beak and talons, flies off to a nearby skyscraper, pigeon in tow, to enjoy its snack.

By now you probably realize that the flash of feathers was one of the peregrine falcons that now call bustling cities like New York home. Mistaking these birds for quick-moving torpedoes is an easy one to make, though, considering that the once endangered birds can reach speeds in excess of 200 mph (320 kph) when they dive for prey [source: Cornell Lab of Ornithology]. These guys could give Dale Earnhardt Jr. a run for his money, no pit stops needed.

When many people are asked to name the world's fastest animal, they immediately think of the cheetah. But if they were to look up at the sky, they'd find an aerial acrobat that can achieve speeds more than three times as fast. With their powerful chest muscles, long wingspan and streamlined shape, peregrine falcons are truly built for speed -- NASCAR couldn't have designed them any better.

Found on every continent except Antarctica, peregrine falcons are the most widespread bird in the world, absent only on isolated islands and in high mountains, expansive deserts and jungles. Although it may be difficult to spot one sitting still, you can identify them by their bluish-gray backs and similarly colored long, pointed wings, as well as the white and black spots on their bellies. They also have black stripes set against their whitish faces, which resemble mustaches.

As fast as they are, peregrine falcons could barely outrun (or outfly) the dangers of Dichloro-diphenyl-trichlorethane (DDT). Beginning in the 1940s and lasting through the early '70s, the entire American peregrine falcon population experienced drastic declines due to the widespread use of this deadly pesticide, which caused their eggshells to weaken and break and led baby peregrine falcons to die before hatching. By 1975, only 324 known nesting pairs, or mating couples, were left. Thanks to some fast action and the Endangered Species Act, the peregrines are speeding back to health and their numbers now stand at about 2,000 to 3,000 breeding pairs [source: U.S. Fish and Wildlife Service].

Peregrine Falcon Speed

There's no doubt about it: Birds are flying machines. They've developed a number of adaptations, many of which have earned them a reputation as aerial acrobats. Their light hollow bones, streamlined feathers, curved wings and strong chest muscles are just a few of the tools that help give birds speed.

Because of the many different variations and gradations of these traits, each of the more than 10,000 species of birds has its own style (or specialty) of flying. Some are gliders, and some are flappers; some reach jetlike speeds, while others cruise by the clouds. The average bird travels a respectable 19 to 37 mph (30 to 60 kph), but the peregrine falcon flies at rates between 40 and 60 mph (64 and 97 kph) -- and that's just a warm-up. [source: Gill, Hayward]. When it really means business, the peregrine falcon can top out at more than three times that [source: Hayward].

What allows a peregrine to fly so much faster than, say, a pigeon? It all boils down to anatomy.

As far as peregrine falcon speed is concerned, a major advantage is the size of its keel. A bird's keel is located at its breastbone, or sternum. As the place of attachment for major flight muscles, it determines the bird's flying ability. Peregrine falcons have especially powerful flight muscles that power their wings to dizzying speeds.

Attached to those large flight muscles is another bonus: pointed wings with slim, stiff, unslotted feathers, which create the streamlined silhouette of a peregrine's body. When some birds rush up against air in flight, they experience drag due to the wind pulling on their loose feathers or broad wings. That may not be a concern if all you want to do is lollygag around in the jet stream, but if you spot a tasty meal, like a pigeon, on the ground, you're going to be glad your body can cut through the air without encountering resistance.

Of course, being able to fly fast means nothing if your heart and lungs can't keep up. That's where the peregrine's aerobic fitness comes in. A bird gets its flight power from the metabolic activity in its muscle fibers. Red muscle fibers, designed to increase oxygen uptake, enable birds to efficiently metabolize energy and maintain prolonged flight, while white muscle fibers fatigue rather quickly. Not only do peregrine falcons have ample red muscle fibers, but their large, strong hearts and highly efficient lungs and air sacs keep their muscles fueled with oxygen. Other birds can't even breathe when flying at speeds half as fast [source: Rizwan].

Living atop high cliffs or buildings doesn't hurt their speed accumulation either, since objects naturally gain speed and lift (from the upward rushing wind), as they descend. If you dived from a building half a mile off the ground, you would probably achieve a pretty good clip as well. Whether you could grab a juicy pigeon at the end of that dive and fly back to your nest and snack on it is an entirely different story.

Frequently Asked Questions

What is the typical diet of a peregrine falcon?

Peregrine falcons primarily eat other birds, such as pigeons, doves and songbirds, catching them in midair during high-speed dives.

How do peregrine falcons hunt their prey?

Peregrine falcons hunt by spotting prey from high altitudes, then diving at incredible speeds to strike and capture their target.