Tuesday, October 17, 2023

Monarch migration has begun. They're 'marathon runners.'

Monarch butterflies fly thousands of miles, often starting in
Canada, to overwinter in Mexico. (Photo by Ron Holmes, FWS)

As summer tips into fall, much of nature shifts with it. Alongside breathtaking leaf foliage and the harvest, autumn includes the monarch butterfly migration from the Northern United States to Mexico.

"Sometime in August, the monarchs from Wisconsin and the upper Midwest start to migrate south. Traveling as far as 50 miles each day, it will take them a month or more," reports Julie Belschner for AgriView. "They often roost at night on trees or bushes. The generation floating on the Midwest winds – as much as a quarter-mile or more high – are those that will overwinter in Mexico for the next six to eight months."

Explaining how monarchs know when to migrate and how they endure the long journey, P.J. Liesch, with the University of Wisconsin Department of Entomology, told Belschner, "It turns out that monarchs have a way to read the earth's magnetic field; essentially metals interact with the earth's magnetic fields, and they use those clues. . . . .Compare the butterflies to a marathon runner. They need carbs. Those butterflies are going from nectar source to nectar source – pit stops, if you will. Have a pit stop ready for them, so if they're passing through, they can pick up what they need." Belschner adds, "Farmers can make a difference by limiting use of pesticides, creating windbreaks and planting nectar plants."

The Fish & Wildlife Service has marked five monarch "super stops" along their journey, reports Julie Morse of the National Wildlife Refuge System.

Iowa
Neal Smith National Wildlife Refuge held its first Monarch Madness Day in 2006. Ninety people caught and tagged 250 monarchs during the day; almost 500 were tagged over the season.

Kansas
The butterflies tend to come in waves based on weather patterns. Migrating monarchs feed on asters goldenrods and other wildflowers that bloom throughout the refuge in the central Kansas wetlands. If winds frustrate butterfly hunters, visitors can catch monarchs inside an enclosed butterfly pavilion.
During the day, look for monarchs in wildflower areas. Toward evening, the best viewing areas are sheltered places that are cool and damp. Monarchs typically visit Kansas in mid-to late September. Check out Quivira National Wildlife Refuge.

Texas
In late September/early October, when conditions are favorable, thousands of monarchs a day may flutter through the prairies and oak savannas of Balcones Canyonlands National Wildlife Refuge in the Hill Country of central Texas.

Virginia
Each year during monarch season (from early September to late October), the Coastal Virginia Wildlife Observatory counts and tags monarchs at the Eastern Shore of Virginia National Wildlife Refuge, at the tip of the Delmarva Peninsula between the Atlantic Ocean and Chesapeake Bay. Visitors are welcome to watch. Taggers record monarch size, condition and gender.

Florida
People start calling St. Marks National Wildlife Refuge as early as August to ask when the monarch butterflies are coming. The refuge is the last refueling stop for thousands of migrating monarchs before they fly over the open water of the Gulf of Mexico.

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