Butterfly Effect: Monarchs Raised and Released by Prisoners Solves Mystery of Migration Patterns

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Floris van Breugel/Nature Picture Library

In what may be the most poetic scientific study ever conducted, dozens of men at a maximum-security prison in Washington state helped uncover migration patterns of West Coast monarch butterflies. The inmates raised and released thousands of the insects over several years so experts could track their long-mysterious flight: a 500-mile journey from the Pacific Northwest to California.

For years, David James, who studies insects at Washington State University, had wanted to examine the migration patterns of West Coast monarchs. The famous route taken by their East Coast counterparts from New York to Mexico had no known Pacific equivalent because the populations are too small to follow. For every 200 butterflies tagged by a researcher, only one is usually recovered at the end of its trip, James says, and finding even 200 in the wild to tag was unlikely. Knowing the route is vital to conservation efforts, but James had no way to figure it out—until he got a phone call from Washington State Penitentiary in Walla Walla.

The prison was looking for new activities to improve the mental health of those serving long-term sentences. So in 2012 he began working with inmates to raise monarchs through their entire metamorphosis—larva to butterfly—at which point the adult insects were tagged and released from the prison. Over five years, nearly 10,000 monarchs flew from the facility. Elsewhere in Washington, Oregon and Idaho, researchers released another few thousand.

The tags included email addresses, and soon after the first butterflies took off, James started receiving messages from people who had spotted them. The butterflies, the reports confirmed, wintered in coastal ­California. Twelve of them landed at Lighthouse Field State Beach in Santa Cruz. Several more headed to Bolinas and Morro Bay. Between 2012 and 2016, citizens found 60 of the tagged butterflies—12 from Walla Walla—that had flown an average of 492 miles; at least one butterfly
traveled 845 miles.

The work helps researchers identify ideal places to plant milkweed and other vegetation that the West Coast monarch population needs to thrive. It also brought out the gentler side of some of the inmates. “They were very worried that they were going to harm the butterflies,” James says, “even though they were in there for doing a lot worse.” Watching the monarch metamorphose also provoked the men. “This butterfly changed,” James recalls inmates telling him, “and maybe we can too.”

With one mystery solved, James is now turning to another: Where do monarchs from Idaho spend their winters? He is already in touch with an Idaho penitentiary.