Last week, I observed how bird-friendly the lyrics are to the Christmas carol “The Twelve Days of Christmas.” In part three of my tribute to the song that just keeps on giving, we run up against the last of the feathered presents: swans. To be precise, seven swans a-swimming. On a recent train ride to Tacoma, I looked out the window at just the right moment to spy swans on Vancouver Lake. I would have liked to ask them if they really go “a-swimming,” but the train was moving too fast.