Each year millions of monarch butterflies migrate thousands

Each year millions of monarch butterflies migrate thousands of miles back and forth from wintering grounds in Mexico to their breeding locations in the eastern United States and Canada. In the fall, the monarchs return to just 12 forested mountaintops in central Mexico, where they form colonies in which millions of butterflies cluster on the trunks and branches of the trees. Despite the creation of protected areas and reserves, illegal logging has been steadily shrinking this unique, critical monarch habitat.