Saving migratory Monarchs

Published 10:00 pm Wednesday, April 15, 2015

A Monarch butterfly alights on a milkweed plant.

A Monarch butterfly alights on a milkweed plant.

After spending the winter in Central Mexico’s high-elevation Oyamel Fir Forest, millions of Monarch butterflies are back on the move this spring.  The insects will travel 25-30 miles a day and up to 1,500 miles, north and east toward breeding grounds stretching from coast to coast across the United States and as far north as southern Canada.

In the fall, 99 percent of North America’s Monarch population makes the return trip to Mexico, migrating to a specific site in the Oyamel Fir Forest to roost for the winter.  In 1993, scientists began recording the number of Monarchs at this site. In 2014, the number of Monarch butterflies reached an all-time low.

According to scientists, the Monarch population in North America has declined by more than 80 percent from its average during the past two decades, and by more than 90 percent from its peak in the mid-1990s.  Currently, the migratory Monarch butterfly population remains very small and very vulnerable.

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North America’s Monarch migration is one of the greatest natural history spectacles on Earth.  While many bird species migrate, the Monarch migration is unique in the fact that it takes place over several generations.  Butterflies flying to Mexico in the fall are the great-grandchildren of insects that departed the previous spring.  These individuals have never seen their winter habitat and how they find their way to these specific sites remains a mystery.

On their wintering grounds, the butterflies show extreme site fidelity and only utilize a small portion of available habitat. Their winter habitat must be warm enough to prevent freezing but cool enough to prevent them from reproducing and burning up fat reserves necessary in order to migrate north in the spring. Therefore, conservationists initially focused on protecting these Mexican forests. Now, the threat to the Monarch stems from the U.S. side of the boarder.  Destruction of habitat across the butterflies’ breeding range is resulting in a significant decline of this truly unique species.

As a result of changing agricultural practices in the Midwest (the main Monarch migration path), host plants for Monarch larvae, milkweeds, as well as other nectar plants needed by adult Monarchs for fuel during migration, are being killed off by herbicides. The conversion of many grasslands and rangelands in the Midwest to a monoculture of corn and soybeans has eliminated much of the Monarch habitat, and pest management on these farms destroys the remaining prairie plants needed by the Monarch (and other pollinators), making the feat of this unique, multi-generational migration and the perpetuation of this species a most difficult task.

In 2014, President Barack Obama met with Mexico’s president and Canada’s prime minister to create a three-nation working group aimed at generating a strategy to protect not only Monarch butterflies but also bees and other pollinators. There is also a petition to list the Monarch butterfly as threatened under the U.S. Endangered Species Act.

Meanwhile, many non-governmental groups, including the Pacolet Area Conservancy (thanks to a grant from Loti Woods), are encouraging their members, partners, and area residents to restore milkweed and native nectar-plant habitat for Monarchs. The need is critical. According to one source, “one million acres of milkweed must be planted annually to keep pace with new losses…it will require this to be one of the largest habitat-restoration programs ever attempted in the world; but it can be done.”

The Pacolet Area Conservancy (PAC) will be working with area schools, clubs, groups, and citizens to raise awareness about the Monarch butterfly, its habitat loss, and restoration efforts.  In the meantime, area residents are urged to plant milkweed, the host plant for the larval stage of the Monarch butterfly.  But, the milkweed must be native to our region and pesticide-free! In addition to planting native milkweed, people are encouraged to plant native nectar plants which will entice the butterflies to the milkweed and provide them with energy to complete their lifecycle.

Please visit the PAC website, under the “Conservation” tab for more information on this topic.

–       Submitted by Pam Torlina