Did you notice that the robins relay messages? The robin in frame is listening to another robin's message, and then repeating it. They''re like a computer network, in that way. Just like dropping a pebble into a pond, the messages radiate outward, transmitting the messages across the continent. I've heard the exact same messages recorded outdoors in KZfaq videos in locations across North America. And those musical notes they sing, made up of 1, 2, 3 and 4 notes with rests in between, most likely make up a language... possibly one of the oldest languages on Earth, since all birds are descended from dinosaurs.