The decline of bee populations has gotten a lot of national attention, but a more flamboyant pollinator is garnering local support for rehabilitation: the monarch butterfly.
“They’re iconic,” said local conservationist and monarch-enthusiast Becky Yeager. “It reminds us of generations past, and there are a lot of older people who love to tell stories about how they grew up with monarchs.”
They’ve been flying around since early June, but the population has been decreasing at an alarming rate for the past three decades, according to Amanda Barth, the rare-insect conservation coordinator for Utah’s Division of Natural Resources.
“Butterfly populations can be fairly variable,” Barth said. “Their numbers can sort of bounce up and down year after year. But these guys have taken a hard bounce down, and then they’ve just stayed low.”
Barth said in the past 30-40 years, more than 90% of the population of western monarchs has vanished.
Yeager became enamored with monarchs after reading a letter to the editor from her then-neighbor Ron Hellstern about the declining butterflies and milkweed patches. Yeager and her two daughters immediately looked through their garden and found a few monarch caterpillars.
But over the years, she’s witnessed the decline continue.
“Just based on my own experience, I had a year where I had almost 300 monarchs that I tagged and released,” she said. “Then it sort of dwindled down to I think 13 two years ago, then it bumped back up to 30 last year. This year, I suspect I’ll have maybe 50.”
While the sightings in Cache Valley have been above-average, according to Yeager, the national average remains so low the western monarch population — an already smaller population than its eastern counterpart — is “potentially at its extinction threshold,” Barth said.
“It’s what we think could be too small for them to recover in the numbers.”
And while Barth acknowledges monarchs don’t play a “keystone role in any kind of ecosystem,” and “they aren’t the most productive and prolific pollinators ... they indicate the health of the environment.”
“When you have a more diverse habitat,” she said, “you have more complete ecological services and functioning.”
However, due to human interference, such as agriculture and economic development, monarch habitats have become fragmented with milkweed removal — the only plant a monarch caterpillar will eat before entering its chrysalis.
And though they’re not the major pollinators, monarchs and other pollinators’ rapid decline will impact the land, according to Jennifer Dowd, who started the nonprofit RAE Environmental to raise awareness of the monarch’s plight.
“If we lose our pollinator population, then everything else starts to be affected negatively, mostly our agricultural production, and also just kind of our connection to the landscape,” she said. “So it’s kind of creating that stewardship and encouraging people to invest in their communities. It just has lifelong implications for generations.”
Dowd — a California-native who moved to Utah for grad school — grew up with the monarchs year-round but said Cache Valley locals are more sentimental about them because of their seasonal appearance. Similar to Yeager, Dowd initially got involved with the efforts to preserve the magic of monarchs for her children.
“A lot of generations of people have always been here to experience it, and then seeing people kind of get saddened by the loss of the population, that’s kind of eye opening,” Dowd said. “So I hope it’s not too late. We’ll see.”
Other factors that may be leading to the decline are the widespread use of pesticides and herbicides in fields, loss of pollinator-friendly plants due to land development so butterflies have no food sources as they migrate, and predators such as birds and other insects.
Some of these factors can be addressed, such as planting native pollinator-friendly plants in gardens and parks to encourage butterfly populations. Then those milkweed plants can be monitored to see if monarchs are using them.
Yeager’s garden, for example, has an abundance of the plant and others for pollinators to visit. She then can place organza bags over leaves with eggs to prevent predation while not removing the monarchs from their natural habitat — something research suggests can be detrimental to the species in the long run.
“There tends to be higher mortality with home-reared caterpillars, in every species, and with so few caterpillars in this population, it just kind of feels like it’s a gamble that I’m not willing to risk,” Barth said.
The fall is especially crucial for monarchs, according to Barth, because the caterpillars emerging from eggs laid at this time are the “super-generation” of the year.
There are typically around four generations of the western monarch per year, with the early generations having about a six-to eight-week lifespan. The super-generation, however, lives roughly eight months.
Utah is on the outer borders of the species’ migratory path, and by November, the monarchs hatching now will have made their way to their wintering sites, such as California and Mexico. When they arrive, they hunker down, only to begin traveling back in the spring.
But this can only happen when the caterpillars have been exposed to the elements, namely the sun.
“Another study has found that as caterpillars are raised out of direct sunlight, or, I should say out of natural light, and they’re kind of in the shade somewhere and under someone’s patio or not having access to normal light ... it messes them up in their abilities to navigate,” Barth said. “So if it is in the super-generation that’s being raised, then they don’t migrate in the correct direction. They kind of just fly anywhere.”
Instead, Barth recommends a hands-off, community scientist approach, like downloading the Survey123 app (found on the DNR’s Monarch Conservation in Utah webpage) and tracking monarchs through photos posted online.
The U.S. Fish and Wildlife Service has been petitioned to consider monarchs an endangered or threatened species, which would make handling caterpillars or butterflies illegal.
“ ... Which will change what we’re able to do significantly here in the valley and elsewhere,” Yeager said. “And we’ll see. There may be some loopholes that allow us to still (tag and raise monarchs) if we have been contributing to community science.”
The decision will be announced this December.
Yeager and Dowd both offer regionally specific milkweed and other pollinator-friendly seeds for those wanting to make their gardens more appealing to declining species of pollinators.