The migrating monarchs of Michoacán © Sylvain Cordier/Getty Images
Probably the most recognizable of all the butterfly species, monarchs are helpful pollinators that can be found across the United States and Canada in the summer. But each fall, millions of these orange and black beauties embark upon one of the world"s most amazing migrations. The insects make use of air currents to make the long journey south to the mountains of southwestern Mexico, a flight of up to 3,000 miles. Aside from being a staggeringly great distance for these delicate insects to fly, it"s also a journey to a place that not one of them has ever been to before. And unlike the many bird species that undertake annual round-trip migrations, these butterflies will never return to the north. Why not? Because the distance and length of the total annual migration cycle is greater than the lifespan of individual monarchs.