After shadows (which are everywhere – Ged's main enemy is a shadow, after all), birds may seem like pretty small potatoes in this book. But still, they're pretty common:
Hmm. Why birds? Why not dragons or dolphins? Or otaks? Well, as much as we love otaks and dolphins, birds have two special qualities: first, they're real rather than mythical, so we all know about birds, and it's easy to picture them. Second, birds fly, which is something that humans can't do. Dolphins swim, but Ged can swim too (or sail, to get over the water), so turning into a dolphin would be neat but not totally new. Flying, on the other hand, is something entirely new for people – people can't fly unless they're wizards or live in a post-Industrial Revolution and post-Wright Brothers world. So the bird-human connection reminds us that wizards are a special. And can also get a bird's-eye view of things.
Ooh, let's not forget that birds sing, which brings us to our third symbol …