It's fall in Panama. Across the U.S., birds fly south for the winter, jaguars and coyotes navigate the jungle corridors, and sea turtles take over the beaches. This narrow isthmus is a vital pit stop for millions of migrating animals, but it's currently in danger. Development, pollution, and climate change threaten to disrupt this fragile throughway. Researchers are scrambling to address these challenges, using modern tracking devices to follow the animals and protect the millions that journey along this unique cross-continental passageway.