Monarch Butterflies migrate great distances

Image: Paul Mirocha

Each year, thousands of Monarch Butterflies choose San Diego as their overwintering site. In August, Monarchs arrive after traveling 1500 miles or more. Monarchs are known to return to the same location—and even the same tree—year after year. What makes this migration more amazing is that no single butterfly makes it more than once. Because of the short life-cycle of the butterfly, each migration is made by Monarchs three or four generations apart.

What causes Monarchs to migrate in the first place? How do Monarch butterflies know when to migrate, and how do the butterflies know to return to the same spots? How do butterflies, weighing less than an ounce, travel dozens of miles each day? Check out the resources below to learn more.

Resources:

Monarch Watch: Unraveling the Great Butterfly Migration Mystery

Paul Mirocha: Where do Monarch Butterflies Go?