Bird migration is the world\'s only true unifying natural phenomenon, stitching the continents together in a way that even the great weather systems fail to do.
Migration paths form an elaborate global web that shows.
Scott Weidensaul follows awesome kettles of hawks over the Mexican coastal plains, bar-tailed godwits that hitchhike on gale winds 7,000 miles nonstop Across the Pacific from Alaska to New Zealand, and myriad songBirds whose numbers have dwindled so dramatically in recent decades.
Bird migration is the world\'s only true unifying natural phenomenon, stitching the continents together in a way that even the great weather systems fail to do