Why is chapter 10 in Gary Schmidt's Okay for Now called "The Arctic Tern"?

"The Arctic Tern" refers to the title of the very first plate drawn by John James Audubon that Doug looked at and admired his first time visiting the library. The plate depicts a bird called an Arctic tern that is actually very symbolic of Doug and the young woman who becomes his girlfriend, Lil. Since seeing the drawing of the bird for the first time, Doug has learned how to create his own drawings, and the lesson of drawing, as well as the Audubon plates, has changed his life. The title of the final chapter of the book reflects just how much Doug's life has been changed by The Arctic Tern and what the bird symbolizes.As soon as Doug sees the plate of the bird, he thinks it's the most beautiful picture he has ever seen. He sees it as a picture of the bird being all by itself and falling without a "single thing in the world that cared at all" (p. 21). What strikes Doug most is bird's "round and terrified eye" (p. 14). He is so struck by the drawing that he visualizes himself as having made the drawing and uses his hand to mimic the motions the artist might have used. As soon as Mr. Powell, an employee of the library, sees his interest in drawing the bird, he begins teaching Doug how to draw. Through Mr. Powell's lessons, Doug learns how to use drawing to forget his troubled home life:

You know one thing that Mr. Powell taught me? He taught me that sometimes art can make you forget everything else around you. (p. 297)

Sadly, however, the city soon begins selling the Audubon plates to pay off the city's debts. Doug makes it a personal mission to restore the plates to the library. Doug sees who has bought the plates, and by performing services, doing favors, and making compromises, Doug convinces the owners to return each plate back to the library. As a result of all he does to restore the plates, Doug matures from a troubled, scared young boy to a brave young man who is now unafraid to tackle his future. Not only does the bird's "terrified eye" in the drawing symbolize Doug's emotions at the beginning of the story, the bird itself is known for its brave and adventurous spirit. Scientists now know the Arctic tern follows the longest migratory route of any bird on record. By the end of the story, Doug and Lil are a bit terrified of their future because Lil is fighting cancer. However, Doug has confidence that they'll bravely, successfully take on the future together and likens the two of them to Arctic terns flying side by side, with Doug being the one ready to "show [her] the next spectacular thing that's going to come into [her] life" (p. 310).
http://www.bbc.com/earth/story/20160603-mystery-migration-solved