The incredible migration patterns of birds varies greatly among species. Some birds, like the Blackpoll Warbler, migrate from the chilly shores of New England thousands of miles to South America, while others, like Bluebirds, simply migrate short distances in search of better food supplies. Birds migrate for many reasons including food supplies and centralized breeding grounds. You may wonder why you never see certain birds migrating south. The answer lies in the different times of day and actual flying heights that different species adapt for safety.
understanding bird migration, with cornell lab of o’s frank la sorte