The Peregrine Falcon is the world's fastest animal;1 it can reach speeds of more than 240 mph during dives. It uses that speed to kill other birds in mid-air. Here's a video of a Peregrine diving and killing a duck, shot with a camera mounted on the falcon's back.
It's cool watching her fly around, but the exciting part starts right around 2:45. The acceleration is incredible. The same bird does a longer and faster dive in this video (at ~0:55):
Here's what the Peregrine's dive looks like from an observer's point-of-view:
Our family had a lively discussion about Peregrine Falcons around the dinner table a couple of weeks ago...I can't wait to show the kids these videos when I get home tonight. (via @DavidGrann)
Although Joseph Kittinger and Felix Baumgartner might quibble with that.↩