Iowans used to see millions of migrating monarch butterflies cross the state. Now they're endangered.
The iconic orange-and-black migratory monarch butterfly is now endangered and one step closer to facing extinction, according to a top wildlife monitoring group.
The International Union for the Conservation of Nature added the migrating monarch butterfly to its "red list" of threatened species in July and categorized it as "endangered" – two steps away from extinct.
“Today’s Red List update highlights the fragility of nature’s wonders, such as the unique spectacle of monarch butterflies migrating across thousands of kilometers,” the organization's director, Dr. Bruno Oberle, said in a news release. “To preserve the rich diversity of nature we need effective, fairly governed protected and conserved areas, alongside decisive action to tackle climate change and restore ecosystems."
The group estimates that the population of monarch butterflies in North America has declined 22% to 72% over the span of 10 years, depending on the measurement method.
The population decline may be noticeable in Iowa, where millions of monarchs cross the state each fall on their way to winter roosting sites in the forests of Mexico.
Monarch butterflies' journey through Iowa
Monarchs live in other places in the world, but the North American populations are the only butterflies to travel so far — up to 3,000 miles — and participate in a two-way migration lasting several months.
Shorter days and cooler temperatures trigger the migratory state of the monarchs. They travel south, feeding on nectar and water, attracted by flowers such as purple aster, thistle and tickseed sunflower.
It is during this yearly migration that millions of monarchs pass through Iowa on their way south.
"It (the monarch population in Iowa) has been declining for the last like 25 years," Iowa Monarch Conservation Consortium program specialist Nicole Shimp said. "We did see from last year to this year, the population did hold steady. But that is after it declined for the last couple years before that."
Monarchs use the sun, and likely the earth's magnetic field, to find their way south. But an unknown instinct leads them to the same location year after year, although they are the great-great-grandchildren of the butterflies that left the previous spring.
They take advantage of high air currents, which allow them to soar like birds and often travel 200 miles a day. They fly solo rather than in groups, though many can be seen feeding in the same area, and they often rest together in trees at night.
Once in Mexico, they cluster in oyamel trees (similar to the fir) by the millions. The trees offer protection from extreme temperatures, predators, rain and snow.
Iowans' efforts to save the monarchs
The Iowa Monarch Conservation Consortium, a group that studies the decline in monarchs and gives guidance on saving them, was formed in 2015 in response to monarch population declines.
According to their website, the consortium is made up of "40 organizations, including agricultural and conservation associations, agribusiness and utility companies, universities and county, state and federal agencies."
The group created the Iowa Monarch Conservation Strategy, which details threats to monarchs and lays out a plan for protecting monarchs' habitats. The strategy seeks to establish approximately 480,000 to 830,000 acres of monarch habitat — milkweed — in Iowa by 2038.
"We really just kind of act to get the word out and help people start establishing habitat," Shimp said. "Iowa is big in agriculture, so we really encourage farmers to enroll some land in the Conservation Reserve Program through the USDA. It really is kind of a win-win, helping increase the habitat and also it's shown that it has really benefited some crops, soil, plants and all that."
These state goals are included in the Mid-America Monarch Conservation Strategy, released by the Midwest Association of Fish and Wildlife Agencies in 2018. The Mid-America strategy outlines goals for the North Central states in the monarch’s northern breeding grounds to collectively establish 1.3 billion new milkweed stems over the next 20 years.
Iowa’s strategy estimates that 127 to 188 million new stems will be established within Iowa, according to the consortium.
"It (the monarchs' decline) can really probably be factored up to about three things: loss of habitat in their wintering location in Mexico, loss of habitat in their summer and spring location, which is here in the Midwest, and then just extreme weather, which we cannot control," Shimp said. "But one thing that we can we can help with in one of those areas is getting more established habitat here in Iowa and the Midwest."
Iowa has seen past efforts at saving the monarch butterfly. In 2015, RAGBRAI cyclists tossed milkweed seed balls into ditches along the ride in an effort to grow more milkweed for monarch habitats.
That same year, the Obama administration launched a plan to increase the number of pollinators and monarchs by seeding habitat along the Interstate 35 "monarch flyway" from Texas to Minnesota, bringing national awareness to the monarch issue.
Still, the United States has not listed monarch butterflies under the Endangered Species Act, despite activists' calls to do so.
The migrating monarch's endangered status should concern everyone, according to Shimp, because of the vital role pollinators like monarchs play in the ecosystem and food supply.
"A lot of reproductive processes of many species of plants and trees need them (monarchs) to pollinate," Shimp said. "They play a big role also in the food chain, along with other pollinators. So it comes down to, you need pollinators to pollinate to make most foods, or the fruits and veggies that go into making most foods."
For more information on monarch butterflies and how Iowans can help rebuild monarchs' milkweed habitat, visit the Iowa Monarch Conservation Consortium website.
Grace Altenhofen is a news reporter for the Des Moines Register. She can be reached at firstname.lastname@example.org or on Twitter @gracealtenhofen.