And they’re off! The annual monarch migration is underway as of March 24, when Journey North citizen scientists in Angangueo, Mexico, spotted a mass of the burnt-orange beauties fluttering northward. After a winterlong siesta in toastier climes, the eastern population will travel all the way to the northern United States and southern Canada. In this, one of the world's most magnificent migrations, no individual butterfly makes it from start to finish. Rather, each successive generation pushes a bit farther north—hitching a ride on south winds you can watch for on this map—then stops to breed. When fall comes, the fourth generation returns to Mexico to start the cycle all over again.
This is just the beginning of their journey, but out of the gate, monarchs have a lot working against them: climate change, habitat loss, pesticides, and parasites have all driven their numbers down. The population counted in Mexico earlier this year was the second lowest on record. Attention green thumbs: Conservationists are calling on you to plant native milkweed and give them the lift they need.
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