Monarch butterflies in Michoacán, Mexico

© Alejandro Prieto/Minden Picture

Flight of the monarchs. Monarch butterflies migrate south

Fall sets in motion a journey of some 3,000 miles for this population of monarch butterflies, who migrate from southern Canada to their wintering habitat in central Mexico. There, they cluster together in fir trees, creating the illusion of orange, fluttering foliage. They’ll remain in their winter roosts until March, when the journey back north begins. But no one individual monarch will complete the full roundtrip, which exceeds the normal monarch lifespan; instead four generations of monarch will hatch as part of the migration, each seemingly driven by an internal compass that guides their flight path.