Monarch butterfly populations continue to drop at alarming rates. Here’s how you can help in Utah

Monarch butterfly tagged on Aug. 17, 2020.

(Utah Division of Wildlife Resources)

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SALT LAKE CITY — Butterflies have been a symbol for humanity's soul throughout history, but as monarch butterfly populations continue to drop at alarming rates, Amanda Barth believes they are now a symbol for something else.

She sees them as symbolic of problems in the ecosystem that pose threats to the future of ever-important pollinators. Their decline is an indication something is wrong.

“They’re like a canary in the coal mine. They indicate the health of the environment and ecosystem,” she said. “If you can make the ecosystem healthier, then you might see more monarchs.”

Barth is the rare insect conservation coordinator for the Utah Department of Natural Resources — a position also supported by a partnership with Utah State University. Her job is to study insects like monarch butterflies and other pollinators — the tiny creatures responsible for helping grow about one-third of all our food — to figure out why they are starting to drop at concerning rates.

So what happened to monarch butterflies and why does it matter?

A massive population decline

First, it’s important to know what biologists are talking about when they say monarch butterfly populations are declining.

Monarch butterflies migrate from warmer winter climates like California, Oregon and Mexico to places all over the West beginning in the spring. There aren’t any population counts for Utah because the species is spread out across the state and region when breeding during the spring and summer months.

According to the U.S. Forest Service, monarch butterflies typically live two to six weeks, but the final generation of the year — the ones that migrate back to the winter habitat — can live upward of nine months. Population counts are calculated during the winter when the species has returned home.

It is counts from the winter locations that have fallen dramatically over the past few decades. Populations gradually plummeted from about 4.5 million in the 1980s to fewer than 30,000 over the past two years, according to the Xerces Society, a national environmental organization that counts butterfly populations every year.

“The really big concern there is, if this is the size of the population, is it too small to rebound? Because it’s hard to know what that quasi-extinction threshold is,” Barth said.

Researchers agree the decline is most likely the result of various man-made causes, such as the widespread decline of milkweed and other flowering plants due to the overuse of pesticides. The plants are where monarch butterflies flock to in their process to lay eggs. Wildfires and changing climate conditions have also threatened monarch butterfly habitats.

Barth explained the species isn’t ultra critical to pollination, but it’s one of the more visible pollinator species that’s more of an important indicator of environmental health for all the other butterflies and insects that are critical for pollinating plants and producing food. If monarch butterflies are declining, then likely so are other pollinator species — and that has been documented to an extent.

One example of another pollinator species suddenly on the decline is the western bumblebee. Once very common, they declined as wildflowers dropped in population, which happened with less rain, Barth said.

“We have several species that have been kind of quietly disappearing,” she said.

The importance of milkweed

Milkweed is considered the “first big step” to knowing if an area is a suitable habitat for a monarch butterfly, according to Barth. The plant is found all over Utah and abundant in some areas. Much like butterflies, milkweed is also declining.

Barth believes that given its name and that it’s toxic, people may see it as an invasive weed and not an important plant that belongs in the ecosystem. The plants produce glycoside, which can be fatal not just to cattle that may graze on the land but also humans; however, it’s important for monarch caterpillars. It absorbs into their wings and helps them become noxious to possible predators, she explained.

Milkweed growing at Stewart Lake Wildlife Management Area in Jensen, Uintah County on Monday, Aug. 17, 2020.
Milkweed growing at Stewart Lake Wildlife Management Area in Jensen, Uintah County on Monday, Aug. 17, 2020. (Photo: Utah Division of Wildlife Resources)

Considered a nuisance, milkweed ends up sprayed with pesticides and herbicides and mowed out of the way.

While she’s not aware of any Utah studies on the topic, California studies have found high numbers of pesticide residue on milkweed even when the plant isn’t sprayed with it. Since it’s not as studied, it’s not known how much of Utah’s milkweed is affected by pesticides or how much the monarch butterflies’ summer habitat conditions have factored in the decline of the species.

That said, experts believe it likely makes a difference.

“It doesn’t necessarily affect the number of monarchs that come into Utah, but it definitely affects the next generation of (butterflies),” Barth said. “If these butterflies are coming in and they’ve mated and they want to lay their eggs down on something and there’s nothing for them to lay their eggs on, then that’s kind of potentially the end of that butterfly and their offspring.”

Working to collect data in Utah

The program Barth oversees, Utah Pollinator Pursuit, began collecting data about a year ago and work continues to collect any sort of data helpful in understanding the decline of monarch butterflies. In fact, she and Utah Division of Wildlife Resources biologists spent time earlier this month surveying monarch butterflies and their habitats in Uintah County.

Since they can’t track populations the same way populations are counted in California, they also rely on community data collectors to track monarch butterfly habitat and butterfly sightings.

Anyone can collect the data and send it to Utah researchers via the organization’s website. Since it launched, they've gotten strong responses to help figure out where milkweed is in the state and where butterflies have been spotted.

“That gives us a much bigger picture, much clearer picture of how monarchs are using habitat in Utah and when,” she said.

A Utah Division of Wildlife Resources member places an identification tag on a butterfly in Uintah County on Monday, Aug. 17, 2020.
A Utah Division of Wildlife Resources member places an identification tag on a butterfly in Uintah County on Monday, Aug. 17, 2020. (Photo: Utah Division of Wildlife Resources)

There’s also the Southwest Monarch Study, which uses tags to track migration patterns. Volunteers capture butterflies and a small tag is placed on the rear of their wing. The tag comes with a specific number that indicates when and where that butterfly was tagged so if researchers come across the butterfly again in another location, they will know how far it traveled. It can also help researchers determine if there’s a specific location that butterflies captured in Utah head to when they migrate for the winter.

Because the data collecting process in Utah is relatively new, they haven’t been able to determine locations where it’s critical to protect in the state or put together other possible applications from the data. That’s something biologists hope to gather quickly.

The group recently began to collect data on bumblebees, as well.

What you can do to help

Some local entities have also worked to improve conditions for monarch butterflies. For example, Salt Lake City Public Lands division tweeted last week that they’ve worked to restore native habits at Fairmont Pond in Sugar House. City officials included a video of a monarch butterfly that had made the park its home for the past couple of weeks.

Those kinds of government efforts on public land are “extremely valuable,” according to Barth. That said, you don’t have to be a government entity to help monarch butterfly habitats. In turn, you help other pollinators.

“Trying to have as native a blend of plants in your garden as possible that flower continuously throughout the summer is really important because that’s also helping other species of pollinators,” she said.

People can volunteer at Utah Pollinator Pursuit habitat events or volunteer at Southwest Monarch Study tagging events.

If gardens, plants or tagging butterflies aren’t your thing, there are other ways you can help Utah researchers with data still needed. Anyone who comes across a monarch butterfly in their yard or elsewhere can take a picture of it and send it to the Utah Pollinator Pursuit website along with the location the butterfly was spotted — or even tag them on Instagram.

“Ultimately we’re going to try data scraping and find out where have we found monarchs in these areas and where are these areas that could potentially receive restoration efforts?” Barth said. “Lots of little things help add up … this is really helpful for us to know if Utah’s butterflies are contributing to the whole (counted) population.”


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Carter Williams is a reporter who covers general news, local government, outdoors, history and sports for


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