Unveiling secrets of a butterfly's magical migration.
When northerners are grabbing snow shovels and huddling against the wind, these insects cling to trees by the millions, overwintering on just 500 acres in Mexico and California. Their orange wings literally cover the boughs. But when the temperature begins to rise and signal spring, the monarchs know: it is time for their migration, the greatest butterfly spectacle on the planet.
Author and ecologist Robert Michael Pyle ...