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Science and the Environment

Effort Continues To Learn More About The Migration Of Monarch Butterflies

Monarch butterflies are on the move.  And citizen scientists are helping researchers learn more about the fascinating insects and their annual migration to and from wintering grounds in Mexico, Texas and California.

Monarch Watch was started 28 years ago at the University of Kansas and is still headquartered there.  Anyone can order monarch tags, catch the butterflies as they migrate through in the fall and tag them.  And if they find a monarch that’s already been tagged, they can take down the information and submit it to Monarch Watch.

An event Saturday at Nathanael Greene-Close Memorial Park at the Dr. Bill Roston Native Butterfly House in Springfield allowed members of the public to tag monarch butterflies as they stopped for nectar on their way to Mexico.

Credit Michele Skalicky
People Line Up to Tag a Monarch During a September 28 Event

Volunteers and staff at the Springfield-Greene County Botanical Center caught monarch butterflies and held them as both kids and adults placed small round tags with adhesive on the back on the insects’ wings.  

Once the tag was in place, the butterflies were allowed to fly off into a nearby garden filled with flowers that provide nectar for the insects.

As the butterflies are tagged, the tag code, tag date, gender of the butterfly and geographic location are recorded.

Monarchs are highly identifiable by their striking black, orange and white wings. 

MSU biology professor, Dr. Chris Barnhart, said monarchs differ from other migratory butterflies in that they travel far and in large numbers and they make a roundtrip.

“The monarchs will fly to Mexico and then the survivors will fly back, and they’ll fly back as far north as Missouri and Iowa,” he said.

Monarch Watch, started by Dr. Orley “Chip” Taylor, has provided a lot of insight into monarch butterflies’ migration over the years.

Credit Michele Skalicky
A Monarch Butterfly is Tagged in Springfield

“These tags are placed on the monarchs at a known time and place, and then, if those individual butterflies are recovered later, you’ve got two points and you can connect the dots and tell how far they’ve gone and how long it took them to get there if the specimen is fresh.”

According to Monarch Watch, tagging helps answer questions about the origins of monarchs that reach Mexico, the timing and pace of the migration, mortality during the migration and changes in geographic distribution.

The idea of monarch tagging began in the 1950s, according to Barnhart.  It was through tagging that the wintering grounds of the monarch were discovered in the mountains of central Mexico in 1975.  At that spot, monarchs roost in trees in a spectacular display.  And monarchs from the Midwest dominate the population there.  Lisa Bakerink, executive director of Friends of the Garden, had a chance to visit the site.

“It’s an incredible experience.--millions and millions of monarchs clustering in trees and flying around if it’s a warm enough day.  It’s kind of monarch heaven,” said Bakerink.

Those grounds are mostly privately owned, she said, but the government offers subsidies to landowners to prevent logging.  However, trees are still being cut down, according to Bakerink, and habitat is disappearing. 

Credit Chris Barnhart
Monarch Butterfly

When you see monarch butterflies in Missouri in the spring, they might have flown to Mexico and are on their way back north.  No one knows exactly how they know where to go each year except that it's instinctual.

But Barnhart said monarch migration is in trouble. 

“The numbers of monarchs have declined precipitously since the mid 90s,” he said.

That’s likely due, in part, to habitat loss, “and that means the food plants for the caterpillars, which is  milkweeds,” Barnhart said.

It’s believed that the increased use of herbicides, now that genetically-engineered crop plants are more tolerant, is to blame for the disappearance of milkweed, which monarchs need to lay their eggs on.

The U.S. Fish and Wildlife Service will determine whether or not the monarch butterfly deserves Endangered Species status under the Endangered Species Act by December 2020.

Homeowners and landowners can help the monarch by planting native flowers such as milkweed and avoid the use of pesticides.  Monarchs rely on nectar-filled flowers to fatten up for overwintering.

And anyone can take part in Monarch Watch.  Barnhart said citizen science is vital in monitoring the migration of monarch butterflies.

“We wouldn’t know what the trends were if it weren’t for the citizen science," he said.

And the decline of the monarch population probably wouldn’t have been recognized without citizens taking an interest in Monarch Watch and recording their results, according to Barnhart.

Learn more about Monarch Watch and sign up to help at