As this video opens, it asks the question: Did you hear about the theory that birds spend the winter in hibernation at the bottom of frozen lakes? No? Of course not, because it's not true. But that's one of the things that many people once believed about birds.
This video by Minute Earth takes a look at theories surrounding bird migration over the centuries. Some of them are way off base. But it also describes the current state of our knowledge about bird migration patterns. Interesting stuff.
(Via Laughing Squid)