Outdoors column: Todd Burras writes plight of migrating monarchs rests in human hands

Todd Burras, Eyes on the Outdoors
Special to the Ames Tribune
Roughly 40 percent of all monarch butterflies that overwinter in Mexico are estimated to come from Iowa and neighboring Midwestern states.

It was a recent email from the National Wildlife Federation that caught my attention while skimming through the inbox, and its headline confirmed what I’d anecdotally observed during the past several days: Monarchs are on the move.

Whether driving home on Interstate 35 from northeastern Minnesota on Labor Day weekend, going for a walk at the Tedesco Environmental Learning Corridor or while enjoying breakfast in our backyard earlier this week, monarchs are suddenly showing up everywhere (albeit not in great numbers but one or two individuals here and there.) And, who among us, doesn’t enjoy being distracted by these delicate-looking beauties that add a bit of whimsy, elegance and grace to a Midwestern landscape?

Each year, at this time, adult Eastern North American monarchs begin their long migration — in some cases up to 3,000 miles — from their summer breeding ranges in the eastern two-thirds of the continental United States and Canada to the fir forests of Mexico’s Central Highlands where they will spend the next five or six months.

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In spring, those same monarchs leave Mexico and fly back to parts of the southern U.S. where they mate, lay eggs and die. Their offspring then begin their northward journey with the first monarchs appearing in Iowa in May. Here they may complete up to three generations of butterflies before the last generation, such as those that we’re now seeing in our yards and along roadways, fly back south to central Mexico where they form their large winter colonies.

The problem in recent years is that these colonies aren’t nearly as big as they once were or should be if they’re going to survive as a species. While it’s encouraging to see monarchs on a daily basis these days it won’t be for several months before lepidopterists (entomologists who study moths and butterflies) have a clear picture of this summer’s monarch reproduction and survival rates. Hopefully, this winter’s population report from Mexico will be better than last year’s.

It’s no secret that the Eastern North American monarch population has been experiencing a precipitous decline for the past 25 years. Last winter, for example, monarchs covered only about 5 acres of forest canopy in Mexico, an area about 2 acres smaller than the winter of 2019 and only about one-third of the estimated long-term average of 15 acres of occupied forest canopy needed to sustain their population and continental migration. That’s according to the results of the 2020-21 annual population report by the World Wildlife Fund, Comisión Nacional de Áreas Naturales Protegidas and the Monarch Butterfly Biosphere Reserve.

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Monarchs face many challenges, including the loss of milkweed (their sole host species plant) and nectar plant habitat in their spring and summer breeding ranges. Exposure to fatally toxic pesticides, forest degradation in Mexico and extreme weather events also have contributed to the population decline. While humans have contributed most significantly to the demise of monarch populations, we also have an opportunity to try and restore their numbers.

Last winter the U.S. Fish & Wildlife Service concluded that adding the monarch butterfly to the Endangered Species Act is warranted but is currently precluded by work on higher-priority listing actions. As a result, the FWS recommended continued implementation of voluntary conservation efforts within the upper Midwest. Those efforts focus on establishment of new milkweed habitat to reach conservation goals.

The current Iowa Monarch Conservation Strategy, according to the Iowa Monarch Conservation Consortium, seeks to establish approximately 480,000 to 830,000 acres of monarch habitat by 2038. The consortium is facilitated by Iowa State University, the Iowa Department of Natural Resources and the Iowa Department of Agriculture and Land Stewardship and works with some 50 organizations, which include agricultural and conservation associations, agribusiness and utility companies, universities and federal agencies.

The consortium’s strategy “guides the implementation of a voluntary, statewide conservation effort based on the best available science” and also “supports habitat improvements in rural landscapes that do not conflict with agricultural production, are sufficient in scale to support improved monarch breeding success and strive to complement other conservation programs.”

Though its ambitious goal is laudable, achieving it in a state where private land is overwhelmingly planted to row crops rather than pasture or Conservation Reserve Program-type plantings that include nectar-producing flowers poses a most daunting challenge. As such, any and all steps each of us take can make a difference, as small as they might be.

With monarchs now making their way to Mexico, it’s a perfect time to start creating a butterfly garden in your yard that will be ready for their return next spring. Since female monarchs lay eggs exclusively on milkweed plants, the best way to lend them a helping hand is to plant milkweed plants. Iowa is home to some 17 species of milkweeds with common, swamp, prairie and butterfly being the most widespread so adding any of those to a garden plot is a good start.

Besides milkweeds, think about including three species of wildflowers (nine species total) that bloom during the early, middle and late portion of the summer. Nectar-rich native flowers suitable for monarchs and numerous other insects and pollinators include Joe Pye weed, prairie blazing star, lead plant, hoary vervain, black-eyed Susan, tickseed sunflower, buttonbush, New England aster, purple coneflower, stiff goldenrod, wild bergamot and field thistle, among many others.

Roughly 40 percent of all monarch butterflies that overwinter in Mexico are estimated to come from Iowa and neighboring Midwestern states, according to the consortium. To learn more about how to help monarchs, visit the Xerces Society for Invertebrate Conservation at www.xerces.org and www.iowamonarchs.info.

Todd Burras can be reached at outdoorstoddburras@gmail.com.