Poo-tee-weet?

In chapter 10 of Slaughterhouse-Five, Kurt Vonnegut concludes the book with a rather interesting phrase. Interesting, that is, to the casual reader who skimmed through just to finish reading for the sake of finishing.  For me, however, I knew the phrase was coming all along. After studying chapter after chapter, I knew how the book would end, and I knew what word would be used.
Vonnegut's conclusion of the book is, "Birds were talking. One bird said to Billy Pilgrim, 'Poo-tee-weet?'" (215). Again, a casual reader would find "Poo-tee-weet?" to be a rather strange way to end the book. However, Vonnegut's purpose with this phrase is directly outlined in Chapter One. As a way of continuing his return into the book's forefront, Vonnegut ended the book just how he said he would at the beginning.
In chapter 1, Vonnegut uses the phrase "Poo-tee-weet?" twice, located on pages 19 and 22. On page 19, Vonnegut says, "And what do the birds say? All there is to say about a massacre, things like 'Poo-tee-weet?'" Vonnegut directly foreshadows what will later happen in the book. On page 215, the survivors of the massacre are clouded in silence: they do not know what to say. However, the bird breaks the silence, just like Vonnegut said it would, by saying "Poo-tee-weet." On page 22, Vonnegut says, "It begins like this: Listen: Billy Pilgrim has come unstuck in time. It ends like this: Poo-tee-weet?"
As a way of connecting the overall frame story from chapter one when it seemed Vonnegut himself would be the main character, he returns to his story at the end to connect with Billy Pilgrim. Furthermore, he ends the story exactly how he said he would, and how I had been anticipating for some time, with a bird. With nothing to say about the horrific bombing themselves, the survivors can only remain silent, but birds are never silenced. To birds, the firebombing was just another event in their lives, so they should just go on tweeting like they knew it would happen anyways. Perhaps Vonnegut is connecting the birds to the Tralfamadorians. Both seem to go on with their lives as if it's all part of the plan and death is unavoidable. So it goes.