For pretty much as long as humans have been thinking about flying, birds have served as our model for getting airborne. In da Vinci's notebooks, sketches of birds sit side by side with his fantastic flying machines and he spent two years compiling a codex of avian flight. Sir George Cayley, the "father of the aeroplane," studied not how birds flapped their wings, but how they were able to glide to the ground and thereby kick-started the heavier-than-air revolution in flight. The Wright brothers, who consummated this revolution, were also well known for their bird-watching habits.
Yet according to new research being spearheaded by the Max Planck Institute of Ornithology in Germany, these pioneers of flight may have been better off watching bats. Over the course of a week in 2009, researchers tracked the flight of seven different Brazilian free-tailed bats residing in the Frio Bat Cave in Texas. What they found was astounding: the bats were capable of reaching ground-speeds of over 100 miles per hour, making them the fastest flying species in the world.
The fastest bird in the world belongs is believed to be the common swift, which can achieve ground-speeds of around 70 miles per hour (peregrine falcons can reach speeds of around 190 mph, but that's when they're diving, not horizontal). This is what makes the finding so astounding: despite having a shorter wingspan and less aerodynamic body shape, the Brazilian free-tail can still reach speeds 30 miles per hour faster than a common swift.
"Initially, we could hardly believe our data, but they were correct," said Kamran Safi, a computational ecologist at the Max Planck Institute of Ornithology. "At times, the female bats, which weigh between 11 and 12 grams, flew at speeds of over 160 kilometers per hour."
The remarkable nature of the finding itself is only surpassed by the researchers' method of data collection. One researcher flew a small Cessna prop plane around the Frio Bat Cave in Texas (home to more than 10 million free-tailed bats) around dusk. Another researcher on the ground would wait for the bats to emerge from the cave and capture one in a net. This bat would then have a half-gram radio transmitter attached to its back and be released back into the column, its radio transmission monitored from the Cessna.
"It was not easy for the pilot to follow the fast-flying animals so that we could localize them accurately and measure their flight path continuously," said Dina Dechmann, a behavioral ecologist at the Max Planck Institute. "External factors like landscape and tailwinds cannot explain these results, as they had no impact on the maximum speeds."
Whether or not the results of this study will impact human aviation design remains to be seen, however if Bruce Wayne's Batgyro is any indication, airplanes modeled on bats would look a hell of a lot cooler.