The monarch butterfly is one of North America’s most recognizable species. This species’ population has dropped significantly in recent years, in part due to loss of milkweed, the food plant for their caterpillars. The Chicago Academy of Sciences / Peggy Notebaert Nature Museum teaches over 5,000 students and community partners through more than 200 workshops each year about monarch butterflies which emphasize the importance of creating monarch habitats, and fosters personal connections with this vibrant, recognizable insect.
About the Monarch Butterfly
The beautiful monarch – with its bold orange, white spotted wings – is perhaps the most well-known North American butterfly. What may be lesser known is that this regal, yet delicate creature makes one of the most arduous voyages of any species, traveling as many as 100 miles per day and more than 2,000 miles during an annual migration from Illinois (or farther north) to their wintering grounds in Mexico. Monarch caterpillars feed exclusively on milkweed. This one, very specific plant is vital to their survival. Without ample access to this species in backyards, fields and waystations along the migratory path, monarchs will perish.
What is the Nature Museum Doing to Help?
Educators with Peggy Notebaert Nature Museum offer more than 200 workshops each year focused on increasing awareness about the monarch’s migration and need for milkweed. Illinoisans can plant milkweed in their gardens to help feed these butterflies.
Biologist Doug Taron also cites climate change as a potential impact to the monarch’s survival, as their waystations in warmer areas of Mexico and Texas play a key role in the migration. The butterfly does well when Texas is green and lush during its migration season – but when its milkweed is dried up, it lacks the resources the butterflies need to survive.
Their migration cycle is what makes the monarch a unique species to North America. While there are several generations of monarchs over the course of the summer, the generation that emerges from their chrysalises in August will adhere to the following migration schedule:
In late August and September, monarch populations as far north as southern Canada begin their migration south to their overwintering sites in central Mexico.
Once the monarchs settle into their overwintering sites, they spend the winter roosting in the fir forests. They do not begin mating until early March – just before they begin their journey northward.
In March, the migration northward begins. When the migrating monarchs reach Texas, they lay eggs on milkweed plants and then die. The butterflies that lay their eggs in Texas each spring are the same individuals that emerged from their chrysalises the previous August. These eggs will hatch and complete their life cycle and begin flying northward. They reach the Chicago area by the end of May.
In most summers, there are three generations of monarchs in Illinois. Adults emerge in late June, July, and August. The caterpillars that emerge from their chrysalises in the late summer will also be a part of the generation that begins traveling to Mexico, thus beginning the migration cycle once more.
How Can I Get Involved?
Become a volunteer, and help spot butterflies. Currently, there are over 100 people counting butterflies on behalf of the Illinois Butterfly Monitoring Network each year. This data is informing conservation strategies for butterflies across the state.
Meet the Expert
“The monarch is one of the most frequently encountered and recognizable butterflies in our monitoring program each year. We encourage Illinoisans to keep an eye out for its striking pattern in September when it nears the end of its migration cycle.”
Doug Taron, PhD
Doug Taron, PhD, is the Chief Curator of the Chicago Academy of Sciences. He founded the Illinois Butterfly Monitoring Network in 1987, a volunteer organization that monitors the health of butterfly populations in nature preserves.