What Animal Is, Relative To Its Size, The Fastest Runner On Earth?
Answer: Tiger Beetle
Tiger beetles are a large family of beetles (roughly 2,600 species and sub-species) found throughout world. While all members of the family are well known for their aggressive nature (both adults and larva are very active predators), not all of them are built for speed (and some of them are downright tank-like in build). Those in the Tiger beetle family with lighter bodies and longer legs, however, are the fastest animals on Earth relative to their size.
The fastest Tiger beetle is capable of running at 5.6 miles per hour. That doesn’t seem remarkably fast, given that even a moderately fit human can easily run faster than that (and an extremely fit human with exceptional skill, like Olympic sprinter Usain Bolt, can hit speeds of nearly 28 miles per hour), but if you were to scale the Tiger beetle’s size-to-running-speed for a human body, then humans would be able to run 480 miles per hour; seventeen times faster than the fastest human.
Although the tiger beetle is capable of sustaining this speed for extended periods of time, they typically run with bursts of speed intermingled with sudden stops. The reason for this halting sprint is not the physical limitations of their legs or endurance, but of their eyes and brains. Tiger beetles move so fast that they are not able to gather enough photons (illumination into the beetle’s eyes) to form an image of their prey, so they pause to reorient themselves, shake off the “blindness” induced by the incredible speed, and re-target their prey if they missed it on the first pass.
Image by L. Shyamal.