When Sammy, a young Wilson's warbler, wakes up one frosty August morning near the Arctic Circle, he instinctively knows that it's time to make his first migratory journey south to Panama. But there's one problem -- where's Panama? All the other warblers having left without him, Sammy sets off on his journey by himself, stopping to ask the same question of each of the different animals that he meets along the way: "Is this Panama?" From the...