People seem to have an innate fascination with speed. We like to watch high-performance cars circle tracks—or tempt speed limits on highways ourselves—and celebrate Olympic athletes like Usain Bolt, who probably is the fastest man on two feet at the moment.

That curiosity often extends beyond machines and elite athletic competition. What has nature done to gift certain animals with enough momentum to overcome prey? And is there really such a thing as the fastest animal in the world?

If all we really want to determine is which animal can cover the distance from point A to point B in the shortest amount of time, then that lingering fact you may have heard about cheetahs is true. The sinewy cat found mainly in Africa can hit speeds of 64 mph, roughly the speed limit of many major U.S. highways. (Other studies have pegged it at 58 mph.)

That’s under ideal conditions. Normally, cheetahs sprint because they’re after dinner, and if that dinner tries to evade capture, the cheetah will need to stop and resume speed often to keep up. Because of the unpredictable nature of their prey, a cheetah often keeps its speed closer to 33 mph.

When we associate the fastest animal in the world with linear forward movement on land, the cheetah is probably going to come out on top. But not all animals use limbs to propel themselves vertically. The falcon, for example, takes advantage of gravity to descend on prey from above. Like free-falling parachutists, falcons have been known to reach high speeds on descent. The higher the starting point, the more speed they can achieve: One peregrine falcon that began at 15,000 feet (thanks to some human help) reached 183 mph.

The cheetah is also outperformed in water by the sailfish, which can reach speeds of 68 mph when they're breaching waves. For context, a sailfish could swim 200 meters in just 10 seconds; Michael Phelps would need well over a minute to cover the same distance. Killer whales can swim 34 mph—incredibly speedy considering their heft.

Asking which is the fastest animal in the world is a tricky question. Humans tend to think of "fast" in relation to the linear movement we see in racing, but fast can mean a variety of things in the wild. While you may never see most of these animals shift into gear in person, at least one domesticated creature can hit the gas: The greyhound tops out at 43 mph.

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