I remember the first time I heard that distinct warbling call. A clear November day, the skies were deep blue and the only clouds were a few very high wispy ones. I heard the warbling while working with my dad outside. I looked around to see where the sound was coming from and couldn't see anything. Later I heard the calls again so I looked, this time I spotted a flock of birds so high in the sky they were barely visible. Their legs were stretched out long meaning the probably weren't geese. They flew like cranes and herons I had seen, but they were in a large flock and at higher altitudes than any crane I had seen. I had never heard any birds like it. I could hear them so easily, their calls carried far and echoed even when they were just specks in the sky. When I inspected the flock more closely, I realized there were dozens of birds. I looked harder and saw another flock higher than that one. From all around they seemed to be joining together until their flock formed into hundreds. I had never seen so many birds migrating together.