Few sights are as majestic as monarch butterflies roosting in trees or flocks of whooper swans migrating across northern skies. Seasonal changes propel a wide variety of creatures to begin migrations—sometimes on an epic scale—to feeding, mating and breeding grounds. This video segment from Nature introduces the story of the seasonal migrations of four different species from across the planet: the wildebeests of East Africa, monarch butterflies of Mexico, sockeye salmon of North America, and whooper swans of Europe.

This video is available in both English and Spanish audio, along with corresponding closed captions.