Across the world, scientists are trying to determine where seasons are shifting. Spring arriving earlier, winter arriving later — it’s happening in many countries. Now, the question is, what will be the consequences of that change.
Starting in 1882, the U.S. Bird Migration Program collected two-by-five notecards from bird watchers around North America. Today, these cards are being digitized. Guest: Jessica Zelt, North American Bird Phenology Program.
