News and Stories

Monarch butterflies flutter among a sea of yellow goldenrod, driven by an internal compass to make their way south to Mexico. This great migration is built into their bones, well technically into their thorax.

Every summer, monarchs migrate to the United States and Canada from their overwintering grounds in Mexico. They travel thousands of miles, flying over mountains, great plains, and rivers for one special plant: milkweed!

This September, as the monarchs are migrating through Cincinnati, Cincinnati Zoo & Botanical Garden Insect Keepers, Zoo Staff, and our Family Community Service volunteers united to “tag” these amazing creatures at EcOhio Farm. A total of 55 monarchs were tagged!

Monarch Watch, a program dedicated to studying monarch butterflies, organizes a nationwide tagging program every year in which volunteers place tags, or small stickers, on the wings of monarchs. When a monarch is recaptured, scientists collect data about its migration journey. Tagging data allows scientists to discover how monarch migration and survival is impacted by changes in the environment over time, which can inform conservation efforts for the declining monarch population.

Monarch populations have decreased by 80% in the past 20 years. But, through Monarch Watch, over 1.5 million monarchs have been tagged during this time, providing valuable information on migration patterns. Continuing to tag monarchs helps scientists learn how changes in climate and habitat across North America impact monarch survival rates, which can inform conservation efforts.

Monarch caterpillars hatch from eggs laid on the milkweed plants. After a few weeks of an all-you-can-eat milkweed leaf buffet, the caterpillars plump up, then pupate (or, change into an adult form) inside a covering they create called a chrysalis. And, once two weeks goes by, the adult butterfly emerges.

Over the next few months leading into autumn, several generations of monarchs hatch up north. The last generation emerging in late summer does not lay eggs on milkweed or mate. Instead, those monarchs spread their wings and fly up to 3,000 miles to Mexico where they will overwinter in a semi-dormant state. The monarch transformation from egg to butterfly is truly amazing!

In addition to tagging monarchs, we also collected 820 milkweed seed pods. The Zoo’s horticulture team will propagate new plants from these seeds over the winter. The new milkweed plants will be outplanted at EcOhio and around the Cincinnati region to support the monarchs when they return to our area again in the spring. Consider planting milkweed in your own yard to help out the monarchs!

Special thanks to Mandy Pritchard, Cincinnati Zoo & Botanical Garden Insect Keeper, and her amazing team of insect experts, as well as University of Cincinnati Biologist Dr. Patrick Guerra for assisting the Family Community Service volunteers with monarch tagging!

“Monarch butterfly populations are declining due to loss of habitat. To assure a future for monarchs, conservation and restoration of milkweed needs to become a national priority.” – Chip Taylor, Director of Monarch Watch