Only a couple of hundred years ago, people weren't sure why birds disappeared in the winter (or the summer, depending on where you are). The idea that birds flew away and came back was common, but where did they go? Other theories were that they hibernated, possibly underwater, or as Aristotle mused, maybe they turned into another species. One Harvard scholar suggested that birds flew to the moon for the months they were missing. And people believed him, because they didn't know how far away the moon is. What they needed was a way to track where a particular bird had been.
Then in 1822, someone in northern Germany shot a stork. The stork was retrieved and was found to have a 31-inch arrow in its neck! We don't know how long the bird survived carrying the arrow, but it was sent to the University of Rostock for study. There it was determined that the arrow originated in central Africa, proof that the stork had flown more than 1,800 miles with an arrow in its neck. Over time, other birds were discovered flying with arrows from faraway places, and scientists confirmed the theory of bird migration. Eventually, we started tagging birds with less painful identifiers. Read about this discovery and how it changed ornithology at Xatakaon. -via Metafilter
(Image credit: Zoologische Sammlung der Universität Rostock)
