Monarch butterflies are some of the most well-known butterflies in North America, due to their large size and deep orange coloring. Their migration from Canada to Mexico and back is nothing short of spectacular, with thousands of butterflies congregating at stops along the way to rest. Often, those stops are monarch waystations, built by universities, nonprofit groups and private citizens to replace rapidly dwindling natural habitats suitable for the butterflies.
One of those waystations, set up in 2011 and maintained by staff from Ohio State's Stone Lab, is located at the South Bass Island Lighthouse. The butterfly garden includes a wide variety of wildflowers, including milkweed, which is essential to the monarchs' life cycle. It is also certified by Monarch Watch, a nonprofit organization based at the University of Kansas that started in 1992 for the purpose of investigating the migratory path, speed and survival rates of monarch butterflies.
"It's amazing that an insect that weighs less than one-fifth of an ounce is able to make a journey of more than 2,000 miles from Canada to Mexico."—Kristin Stanford
"It's amazing that an insect that weighs less than one-fifth of an ounce is able to make a journey of more than 2,000 miles from Canada to Mexico each fall," said Kristin Stanford, Stone Lab education and outreach coordinator, who helped initiate the waystation project in 2011. The timing of the trip is critical: Monarchs are unable to withstand freezing temperatures and can't fly if it gets too cold. Because the butterflies' bodies also aren't well-suited for long flights, they rely on tailwinds and thermals, and they have to rest often.
Southbound Monarchs will congregate in places like the southern tip of Pelee Island on the Canadian side of Lake Erie, waiting for the perfect flight conditions.
The Great Lakes present a geographic hurdle for the monarchs, both because the long stretches of water require flight without rest, and because winds can shift quickly above the water, blowing the butterflies off course. Monarchs will therefore congregate in places like the southern tip of Pelee Island on the Canadian side of Lake Erie, waiting for the perfect flight conditions. Once they successfully make the crossing, Stone Lab's waystation at the lighthouse provides a perfect resting spot for the monarchs. This is also when Stone Lab staff tag the butterflies as part of Monarch Watch's tagging program.
"In 2012," Stanford said, "we were able to catch, tag and release 254 butterflies on their way to Mexico."
Read the whole story (pdf; p. 14) …
-- Jackie Taylor, Lake Erie Islands Nature and Wildlife Center, and Christina Dierkes, Ohio Sea Grant Communications