Migration was difficult to know.  It’s not surprising.  Who could say why birds leave for a time, where they go?  Aristotle thought that birds just transmuted into a different species when the weather changed. Later, it was assumed that birds hibernated. Charles Morton believed they flew to the moon. Even in the 19th century naturalists agreed that swallows spent the winter sleeping in the mud at the bottom of lakes. The first clue of migration was a dead stork, shot by a German nobleman, found to have an African arrow embedded in its neck.  They’re called pfeilstorchs, and 25 were later documented.  Shot in Africa, they still obeyed the call and went home. Thanks to the spears we finally understood them.  We’ve long known this, that violence is a path to knowledge. The shattered faces of the Great War gave us reconstructive surgery. The V2 gave way to the Apollo program. I’ve been having less luck, stabbing a volume of Jack Gilbert in the dark, burning my own poems, burning my hands. The word doesn’t come any easier.