Is extinction coming for Monarch butterflies? Why Idaho’s state insect needs protection
Jerry Pugh had a rare experience this year: He saw a monarch butterfly in the wild.
Though the Boise Parks and Recreation volunteer coordinator works to conserve the endangered butterfly, sightings for him have been few and far between.
“I saw a female monarch this year,” Pugh told the Idaho Statesman. “That was the first monarch that I’ve seen in the wild in three years.”
Millions of monarchs inhabited the Western U.S. in the 1980s, but recent counts have been in the thousands, a decline of more than 99%. Recently classified as endangered, Western monarch butterflies have made a modest return, offering a glimmer of hope for Idaho’s state insect.
This number of monarchs this year is its highest since 2016. And until the orange and black insects begin their migration south, lucky Idahoans may still see one in the coming weeks.
Monarchs west of the Rocky Mountains spend winter on the California coast, and experts count these overwintering populations to predict the Pacific Northwest’s summer monarch numbers. The Xerces Society for Invertebrate Conservation found 250,000 monarchs in 2021, over 100 times the previous year’s perilous count of less than 2,000.
The Pacific Northwest’s wet spring led to more abundant milkweed, a plant essential to monarchs’ survival, Washington State University entomology professor David James said. The insect’s development and survival also seems to be strong this year.
“If you want to see a monarch, the best opportunity is going to happen over the next four weeks around milkweed patches,” James said. “But who knows what will happen in the future — they could go back down again.”
The butterflies must contend with less milkweed, hotter temperatures and even increased traffic.
Monarch declines linked to habitat reduction
Monarch larvae only eat milkweed, a tall, flowering plant that oozes a milky-white sap. They are immune to the plant’s toxins, and predators know to avoid the monarchs’ poison-filled bodies.
“Where there’s milkweed, you’ll find monarchs,” James said.
While milkweed is common along the green and wet Snake River region, agriculture, urban development, and other changes in land use have reduced milkweed across North America, leading to fewer monarchs, James said. And temperatures over 100 degrees Fahrenheit suppress monarchs’ ability to reproduce and live longer — causing population declines over time.
Pesticide use may also impact the butterflies’ lifespan and reproductive abilities, James added.
There may be other minor factors too, James said, such as motor vehicle traffic collisions with butterflies.
Monarchs embark on multi-generational migration
In the fall, Idaho’s monarchs will travel to the California coast, beginning a migration pattern that confounds scientists who study them.
In California, the butterflies will roost together in trees and wait out the winter. Come spring, they will begin the journey back home.
As the monarchs fly north, they will have children and grandchildren with lifespans of just a few weeks. These descendants are the butterflies that will make it back to their ancestors’ summering grounds in Idaho and beyond until another migratory generation is born in the fall.
“That second and third generation doesn’t know where to go, but somehow it does — it really is kind of a mystery,” Idaho Fish and Game biologist David Dressel told the Statesman.
Some scientists theorize that monarchs are guided by Earth’s magnetic fields, the position of the sun, or weather patterns. But no one has a definitive answer, Dressel said.
Idaho Fish and Game investigating migratory patterns
Dressel is part of an ongoing Idaho Fish and Game project to demystify monarch migrations and enhance monarch habitat in Idaho.
The scientists want to pinpoint the route that butterflies take when they leave Idaho in the fall for California and even Mexico. A better understanding of migratory paths can help them target where to target habitat enhancement projects, such as planting milkweed, Dressel said.
This fall, he plans to catch monarchs in the field and tag them with electronic nano pins — compatible with a new tracking system connected to a series of towers placed across several Western states, Canada, and Mexico.
Scientists receive data whenever tagged animals fly past these towers, allowing them to figure out how monarchs are traveling to their southern destinations, Dressel said. This year, the team plans to tag and track 15 monarchs.
But Dressel said monarch scarcity makes sample size a challenge.
Boise commits to monarch conservation
Earlier this year, Boise Mayor Lauren McClean took the National Wildlife Federation’s Mayors’ Monarch Pledge, joining over 600 mayors and local leaders in the fight to save monarch butterflies.
Boise Public Library library assistant Alene Hortin and Boise Parks and Recreation community volunteer specialist Kristin Gnojewski are forming a task force to focus on meeting the pledge requirements, such as increasing monarch habitat within the city and supporting community science monarch monitoring projects.
With Boise’s Parks, Monarchs, and Milkweeds Program, volunteers can monitor milkweed patches throughout the city — looking for eggs, larvae, and pupae. Citizen scientists, like Pugh, submit monarch and milkweed observations to a national database.
The city also maintains several pollinator gardens to support monarchs and other pollinators such as bees, moths, beetles, and flies.
Ada Soil & Water Conservation District runs the Treasure Valley Pollinator Project, which sells pollinator plants for yards to improve biodiversity. To support monarchs, the packages of plants included milkweed this year, said Jessica Harrold, Ada Soil & Water Conservation District program coordinator.
“Pollinators are a huge foundation of our food chain,” Harrold said, since they pollinate crops, are food for prey, and break down waste.
And while monarchs aren’t the most important pollinators, many animals depend on them, James said. But there’s more to monarchs than their ecological role, he added.
“Butterflies, I think, should be treated like works of art,” James said. “They’re as beautiful as a painting or a piece of music.”
Monarchs are also an indicator species, James said, since they are one of the first organisms to suffer when the environment is changing. If butterflies suffer, so will other animals — and ultimately humans.
“They’re a bit like a canary in the coal mine,” James said.
