Why are there still so many people who believe that cheetahs are the fastest animals alive when it's clearly peregrine falcons?
Listen, it’s all in how you’re going to split hairs or various other integuments on this one. Without any qualifiers, peregrine falcons are the fastest animal. However, they hit their record speeds of 320km/hr+ in free-fall - so, once you start getting into “fastest animal moving under it’s own power”, things get messy. When it comes to powered flight, peregrines only hit about 65-90km/hr.
Cheetahs aren’t even a close second in the unqualified “fastest animals” category though, with their speeds of ~120km/hr; a whole slew of other speedy birds
who enjoy plummeting to their deaths just haphazardly smashed their way in there with no regard for those poor earth-bound mammals.
So let’s get into some qualifiers. Fastest self-powered movement? Nope; Brazilian free-tailed bats noodle around at a casual 160km/hr - and, as you may notice, this also means cheetahs aren’t even the fastest mammal. It’s only once we rule out everything that isn’t a terrestrial mammal that cheetahs finally take the crown. You tried, cheetahs.
This isn’t even going into speed options beyond our restrictive, human-sized measurements - for instance, in terms of objective body lengths per second the Southern California mite just absolutely crushes it with 322 body lengths per second (whereas cheetahs only score at about 16). To translate, this is the equivalent of a human running 2,092km/hr.