The Monarch Mystery

Sep 9, 2011

Thousands of monarch butterflies are fluttering through eastern South Dakota on their way to Mexico, where they will spend the winter.  Their annual migration has stumped scientists for decades. This generation of monarchs has never been to Mexico, so how do they know where to go?

To better understand the mystery, here’s a brief synopsis of the monarch life cycle. In the spring, when monarchs head north, they fly only a short distance before they lay eggs. That dramatically shortens their life span, and soon they die. The cycle repeats through the spring, so the butterflies that eventually arrive in South Dakota may be the great-grandchildren of the monarchs passing through right now. Theoretically, they shouldn’t know a thing about Mexico.

On Thursday, a group led by Jody Moats of the Adams Homestead and Nature Preserve gathered at Spirit Mound north of Vermillion to tag monarchs. The tiny, sticky dots affixed to a wing help researchers track their flight and provide other data that might someday help solve the monarch mystery. Click the image above to watch a short video of the tagging.