Why is chapter 10 called "The Arctic Tern"?

Doug has a rough life.  His brothers are criminals in the making, and they abuse him almost as much as his father does.  Doug's father is not afraid to verbally and physically abuse Doug, and alcohol only makes it worse.  Doug has also been moved to a new city and new school, which means his close friend Holling Hoodhood can't be there for him.  All of these things pile up on Doug and give him a bit of a rough edge, which his teachers don't respond too well to at first either.  About the only thing in Doug's life that offers him comfort and peace is looking at the "Arctic Tern" plate painting by John James Audubon in the public library.  
Doug's closest friend, Lil, is also sick with cancer.  The doctors give her a one in four chance of surviving.  She's not doing well.  In chapter ten, Doug goes to visit her several times, and in the final moments of the chapter Doug is by her side again.  It's clear that Lil is scared.  She's shaking and crying, and Doug reaches out to hold her hand.  He tells her to think of "a whole lot" of Arctic terns flying around her.  He tells Lil to imagine them showing her the next great thing that is going to come into her life.  The sequence is incredibly sad, yet it is a hopeful scene as well.  Lil is comforted by imaging the terns, and throughout the novel, the image of the Arctic tern has offered comfort to both Doug and Lil.  It's appropriate to name this chapter after such a hope giving image.