Planting Milkweed for Monarchs? Make Sure It’s Native

Butterflies are vanishing out West. Scientists say climate change is to blame.

The rate of decline is “calamitous,” one scientist said, and has implications for crops and the environment

By Dino Grandoni

March 4, 2021 at 1:00 p.m. CST

The Monarch butterfly is one of hundreds of butterfly species vanishing in the American West because of climate change. (Kevin Sieff/The Washington Post)

Hundreds of butterfly species across the American West are vanishing as the region becomes hotter, drier and more vulnerable to the effects of climate change, according to a study released Thursday.

In a swath of 11 states, from California to Montana, and from New Mexico to Washington, the populations of a majority of 450 butterfly species are dropping, according to observations by professionals and amateurs stretching back to the 1970s.

The loss of butterflies across Western forests and prairies, like the similar drop in bumblebees nationwide due to rising temperatures, is troubling because both insects play a key role in pollinating crops and wildflowers. And the findings may add to fears among researchers of a broader die-off of insects that could be underway everywhere from Germany to Puerto Rico and beyond — a potential and debated bugpocalypse that threatens to upend ecosystems across the world.

In the United States, the alarming butterfly decline is most evident in Western areas where balmy summer temperatures creep well into the fall, drying out vegetation and potentially disturbing the seasonal cycles of the fluttering insects as they prepare for cooler months.

“The influence of climate change is driving those declines, which makes sense because they’re so widespread,” said Matt Forister, a biology professor at the University of Nevada at Reno and co-author of the study published in the journal Science. “It has to be something geographically pervasive.”

Scientists have long known that roadways, farms and other human development are stamping out meadows and other habitat for butterflies, while pesticides have further culled their numbers. Conservationists have taken to cordoning off areas as butterfly sanctuaries, planting vegetation such as milkweed for monarch butterflies as they migrate from Mexico across the Lower 48.

But the fact that widespread warming is weighing on such large numbers of butterflies across a vast geographic area suggests a more dire situation that cannot be abated simply by setting aside habitat. While the populations of butterfly species can vary widely from year to year, the researchers found an annual 1.6 percent drop in butterfly numbers in the Western United States over the last four decades.

Put another way: A butterfly spotter going to the same site every year saw about 25 percent fewer butterflies on average than 20 years ago.

David Wagner, an ecologist at the University of Connecticut who was not involved with the latest research, said the new findings are startling because “this is one of the first global cases of declines occurring in wildlands, away from densely populated human-dominated landscapes, and the rate of 1.6 percent is calamitous.”

The best-known butterfly on the decline in the drought-plagued region is the once-ubiquitous monarch, which used to arrive in California in such abundance every spring they regularly formed “a golden carpet” on the ground and filled the skies with “orangy” clouds, as John Steinbeck once wrote.

Now those orange itinerants are showing up in far fewer numbers. Since 1990, about 970 million monarchs have disappeared, according to a 2015 U.S. Fish and Wildlife Service report.

The Vanessa cardui, a type of painted lady butterfly, is also under threat. (Justin Sullivan/Getty Images)

Other species, such as the common cabbage white butterfly and the imperiled, multicolored Edith’s checkerspot, are on downward trends, too, according to the analysis from Forister and his team.

“Rare species, common species, widespread species, local species,” said Forister, each had “detectable declines.”

The formal scientific findings jibe with what many motorists driving across the West have noticed recently: fewer bugs splattered across the front of their cars than during past road trips. Entomologists even have a name for it: the “windshield phenomenon.”

Forister said he has seen it “personally because I’ve been driving back and forth over the mountains for 20 years” from Reno and elsewhere on Interstate 80 to visit his parents in California’s Central Valley.

“It used to be that as soon as I showed up, my dad would get the hose out and obsessively clean the window,” Forister said. “He just doesn’t even do that anymore.”

The latest research is built on not only data collected by scientists across central California but observations across 10 other Western states scribbled into notebooks by butterfly enthusiasts out in the field or simply uploaded from smartphones by amateurs who make a hobby out of spotting rare species in their backyards.

“Even if you just took the professors that were on this paper, all of us, we couldn’t cover that geographic area,” said Katy Prudic, an entomologist at the University of Arizona who helps run one of the online butterfly databases. “There’s just not enough of us. So this work, the comparison across the entire West, could not be done without citizen science.”

Among the data used in the study are field notes from Marilyn Lutz and her husband, Joe Zarki, who have volunteered to run a butterfly count in Joshua Tree National Park for 25 years. The couple has been cataloguing birds and butterflies together ever since meeting in Yellowstone National Park in 1985.

They used to think they had trouble finding certain butterflies at higher elevations due to lack of experience. “But over time, we’re wondering if some of these are species that may be climate-change influenced,” said Zarki, who used to run educational programs at the park and is now retired.

Not every type of butterfly is in decline. Some are finding an edge in environments dominated by humans. The bright-orange Gulf fritillary, for example, is thriving not on native plants but on flowers popular in home gardens, Forister said.

And climate change itself may be a boon to butterflies in some places outside of the arid West. Using some of the same data as Forister and his team, Matthew Moran, a biology professor at Hendrix College in Arkansas, is working on a paper that he says will show an uptick in butterflies in the southeastern United States, where climate change is leading to more precipitation and plant growth.

“They got a really strong climate signal,” Moran said of the study published Thursday. The Western United States, he said, is “one of the more rapidly changing places in the continent. … If you look at it more continentwide, you will see more balancing-out.”

Still, efforts by federal wildlife officials to protect those butterflies in danger of vanishing entirely have had limited success. Of the 31 butterflies protected under the Endangered Species Act, only three are increasing in number, according to Noah Greenwald, endangered species director at the Center for Biological Diversity, a nonprofit environmental advocacy group.

Conservationists have struggled to get other imperiled butterflies added to the endangered list. In December, the Trump administration declined to declare the monarch endangered, citing limited resources, even as wildlife officials admit the decline is severe enough to warrant federal protection.

And the Center for Biological Diversity has fought for years to get the Sacramento Mountains checkerspot butterfly, a native of New Mexico’s high-elevation meadows, listed as endangered, filing multiple petitions with the Fish and Wildlife Service, including a new one this week.

Even so, it could be too late. “Now they can barely find it,” Greenwald said. “It may be extinct.”

Dino Grandoni Dino Grandoni is an energy and environmental policy reporter and the author of PowerPost’s daily tipsheet on the beat, The Energy 202. Before The Post, he was the climate and energy reporter at BuzzFeed News, where he covered the intersection of science, industry and government.

Fear in Mexico as twin deaths expose threat to monarch butterflies and their defenders

The deaths of two butterfly conservationists have drawn focus to a troubling tangle of disputes, resentments and violence

The Guardian

by David Agren in Ocampo and Oliver Milman

Sat 8 Feb 2020 10.19 EST

The monarch butterfly weighs just half a gram but flies 3,000 miles south each year to winter in central Mexico. Photograph: Gregory Bull/AP

The deaths of two butterfly conservationists have drawn focus to a troubling tangle of disputes, resentments and violenceby David Agren in Ocampo and Oliver MilmanThe age of extinction is supported by

Sat 8 Feb 2020 10.19 EST

The annual migration of monarch butterflies from the US and Canada is one of the most resplendent sights in the natural world – a rippling orange-and-black wave containing millions of butterflies fluttering instinctively southward to escape the winter cold.

The spectacle when they reach their destination in central Mexico is perhaps even more astonishing. Patches of alpine forest turn from green to orange as the monarchs roost in the fir trees, the sheer weight of butterflies causing branches to sag to the point of snapping. Tens of thousands of the insects bounce haphazardly overhead, searching replenishment from nearby plants.Q&A

What is so special about monarch butterflies?

To witness this sight is as if to enter a waking dream. “People have a spiritual and emotional connection to monarchs,” said Sonia Altizer, a monarch butterfly researcher at the University of Georgia. “Many people tell me that seeing them was a highlight of their life.”

The recent deaths of two butterfly conservationists in the region has, however, drawn attention to a troubling tangle of disputes, resentments and occasional bouts of harrowing violence that has lingered over the Monarch Butterfly Biosphere Reserve, a sprawling world heritage site situated 60 miles north-west of Mexico City.

Mustachioed and gregarious, Homero Gómez González tirelessly promoted the El Rosario sanctuary, a section of the butterfly reserve that receives the bulk of tourists who come from around the world to see the monarchs. He featured in mesmerizing social media videos – posing with butterflies fluttering around him – and called the creatures “a marvel of nature”.

Gómez, who was 50, disappeared on 13 January after attending a patron saint festival in the municipality of Ocampo; his body was found two weeks later at the bottom of a watering hole. His death has yet to be ruled a murder, although police say he suffered a blunt trauma to the head.


The incident raised fears that gangs, possibly tied to the illegal logging of the butterfly reserve, had targeted Gómez for his advocacy of ecotourism over the felling of trees in this rugged swath of Mexico where communities, often beset by poverty, have traditionally relied upon the harvesting of timber, potatoes and wheat.

Fir branches sag under the weight of countless monarch butterflies. Photograph: Chicago Tribune/TNS via Getty Images

Those concerns were further heightened this week after the death of a part-time tour guide from another nearby butterfly sanctuary, called Raúl Hernández Romero. His body was found 1 February with injuries possibly inflicted by a sharp object.
“The panorama for the community, the forest and the monarch butterflies is now very complicated and uncertain,” Amado Gómez González, one of Gómez’s nine siblings, told the Guardian.

“There are now these two crimes and it has spread fear. You find yourself thinking ‘What if this is a group that is coming to try and take the sanctuary away from us?”

Investigations into the two deaths are ongoing. But some conservationists fret they are a byproduct of the violence that has long troubled the state of Michoacán, which stretches from the mountains of central Mexico to the west coast.

As they have done across the country, organized crime groups linked to the drug trade have diversified into many other activities, including kidnapping, avocado cultivation, land theft – and the lucrative market in pine, fir and cedar wood.

Logging is supposedly under tight controls, but high prices mean lumber mafias often stray into protected areas – and are prepared to use violence. “In Michoacán, a tree is worth more than a human life,” said one former state official.

“Homero Gómez was in conflict with these loggers,” said Homero Aridjis, an environmentalist and poet, who is a longtime defender of the monarch butterfly sanctuaries. “They’ve always been a very dangerous group because there are always politicians, businessmen involved in deforestation.”

People mourn next to the coffin with the remains of Mexican environmentalist Homero Gomez, during his funeral in El Rosario village, Michoacán, on 30 January. Photograph: Enrique Castro/AFP via Getty Images

Aridjis said his own activism against illegal logging, the planting of avocado orchards and the proposed construction of a mine near the sanctuaries has brought threats. He largely stays away from the butterfly sanctuaries due to security concerns.

But others suggest Gómez may have fallen foul of a backlash to his buccaneering self-promotion and questions over his role as the former leader of the El Rosario community, which is run as an ejido – a traditional Mexican collectivist arrangement where residents share ownership of the land and its bounty.

“In this system, it’s easy for a leader to become abusive with the community’s income,” said a Michoacán conservationist who was familiar with Gómez and the sanctuary but did not want to be named. The conservationist insisted it was still safe for butterfly guardians to do their work.

“He was an outspoken person, he drew a lot of attention to himself. I don’t know why he was killed, but because of the non-transparent management of the ejido he had a lot of enemies. It’s difficult to say this in Mexico because the press has portrayed him nearly as a saint.”

Regardless, Amado Gómez’s fears that “large groups” might seize the sanctuary are not without foundation. Criminal groups have already moved in on resources such as water, forests and minerals – most famously in the indigenous Purépecha community of Cherán, where locals rose up in 2011 to halt illegal loggers, backed by a drug cartel, from clearcutting their forests.

The demise of Gómez also highlights the misery suffered by Mexico’s beleaguered environmental defenders, who have been murdered with impunity in shocking numbers. Fourteen defenders were murdered in Mexico in 2018, according to Global Witness.

Security concerns are rife in the region, and many prefer silence. “It’s very difficult [to speak out], and even more so for those who live here,” said a local researcher, who preferred to remain anonymous.

While the reasons for the deaths of the two men have yet to fully emerge, concerns are already swelling that the incidents will hurt tourism. The fragile security situation across Mexico has been blamed for a quiet winter for visitors in one of the major sanctuaries, Sierra Chincua, even before the deaths.

The monarch butterflies themselves are also coming under growing pressures. A historic low in overwintering populations was recorded in 2013-14, amid a longer-term slump that has prompted mayors in cities across North America to promise remedial action. It’s suspected that butterfly numbers have been winnowed away by the use of toxic pesticides and razing of critical monarch habitat in the US and Canada.

The decline was reversed somewhat last year but scientists warn the annual monarch migration faces an existential threat due to the climate crisis. The oyamel firs preferred by monarchs in Mexico are being stressed by rising temperatures and drought, with predictions the trees will be virtually wiped out by the end of the century.

Global heating is also reducing the viability of milkweed, the sole plant where the monarch reproduces, in US and Canada. This trend is set to restrict the butterflies to isolated pockets and end their epic migration to Mexico, a journey that can stretch for 3,000 miles. A separate monarch migration, which brings butterflies to the warmth of coastal California, has shrunk from millions of insects in the 1980s to fewer than 30,000 individuals now.

Monarch butterflies fly near a tree at the Sierra Chincua butterfly sanctuary on a mountain in Angangeo, Michoacán.Photograph: Carlos Jasso/Reuters

“It’s so obvious that it’s painful,” said Orley Taylor, a biologist and co-founder of Monarch Watch, a group of US volunteers focused on studying and conserving the species. “Within 30 years or so we probably won’t be talking about the monarch migration. We risk losing something very special indeed.”

The demise of the overwintering monarchs would send an economic and cultural shock through central Mexico, although there are currently more pressing concerns in a region beset by crime and few economic opportunities.

“People are all for protecting the butterflies, but people have to have the necessities to survive,” said Father Martín Cruz Morales, a local priest, on a break from a community lunch of tacos and aguas frescas to celebrate the anniversary of a colleague’s ordination.

In El Rosario this week, Gómez’s friends and family packed a billiards hall – emblazoned with the image of Homer Simpson – to pray the novena, or nine days of prayer.

Over pastries and hot cups of fruit punch, Amado Gómez remembered his brother, a former logger, as an ambitious but often altruistic man, who graduated from Mexico’s premier agricultural university and mostly worked in government until launching his activism in favour of the monarch butterflies.

Homero Gómez led tree-planting initiatives in El Rosario. He also helped organize patrols to protect the forests; teams of 10 persons still head out day and night into the hills to guard against incursions from illegal logging – something that locals say hasn’t occurred in the butterfly reserve for at least two years.

“They know that people are organized here and know that it’s difficult to cut down a tree and escape,” Amado Gómez said. “Nobody trusts the local police so they do [security] themselves with sticks, with guns, with whatever they can use themselves.”

Women dressed as monarch butterflies perform during the Day of the Dead Parade in Mexico City on 27 October 2019 in Mexico City. Photograph: Cristopher Rogel Blanquet/Getty Images

Altizer, the University of Georgia researcher stressed that she didn’t think the reserve was too dangerous to visit and argued that tourism and conservation efforts should continue as before.

“El Rosario has so much to offer tourists, it’s right in the core of the biosphere reserve,” said Altizer. “If you think any place should be safe for monarchs and people it should be there, which makes this shocking. It makes me wonder if this will deter tourists from going there in the future. It sends a worrying message.”

She said scientists have long been advised to be cautious in the region, to not drive around at night and to avoid certain areas. A vehicle owned by the WWF had to cover its logo up on a previous visit due to fears of attack.

“You see federal police patrolling the forest in military-style vehicles which is a little disconcerting,” she said.

“There is drug cartel violence in Michoacán, and if that bleeds over into logging operations I don’t know what the best strategy to combat that is. People in these communities already have to deal with a lot of hardships. It’s difficult to promote ecotourism when logging continues even after the designation of the biosphere reserves.”

‘A cause for worry’: Mexico’s monarch butterflies drop by 26% in year

The Guardian – AP in Mexico City

The butterflies’ population covered only 2.1 hectares (5.2 acres) in 2020, compared to 2.8 hectares (6.9 acres) the previous year. Photograph: Luis Acosta/AFP via Getty Images

AP in Mexico CityThu 25 Feb 2021 17.09 EST

The number of monarch butterflies that reached their winter resting grounds in central Mexico decreased by about 26% this year, and four times as many trees were lost to illegal logging, drought and other causes, making 2020 a bad year for the butterflies.

The butterflies’ population covered only 2.1 hectares (5.2 acres) in 2020, compared to 2.8 hectares (6.9 acres) the previous year and about one-third of the 6.05 hectares (14.95 acres) detected in 2018, according to government figures.

Because the monarchs cluster so densely in pine and fir trees, it is easier to count them by area rather than by individuals.

Gloria Tavera, the regional director of Mexico’s Commission for National Protected Areas, blamed the drop on “extreme climate conditions”, the loss of milkweed habitat in the United States and Canada on which butterflies depend, and deforestation in the butterflies’ wintering grounds in Mexico.

A monarch butterfly is seen at El Rosario sanctuary for monarch butterflies in the western state of Michoacan, near Ocampo, Mexico. Photograph: Alan Ortega/Reuters

Illegal logging in the monarchs wintering rounds rose to almost 13.4 hectares (33 acres), a huge increase from the 0.43 hectare (1 acre) lost to logging last year.

Jorge Rickards of the WWF environmental group acknowledged the lost trees were a blow, but said “the logging is very localized” in three or four of the mountain communities that make up the butterfly reserve.

In addition, wind storms, drought and the felling of trees that had fallen victim to pine beetles or disease, caused the loss of another 6.9 hectares (17 acres) in the reserve, bringing the total forest loss in 2020 to 20.65 hectares (51 acres). That compares to an overall loss of about 5 hectares (12.3 acres) from all causes the previous year.

Tavera said the drought was affecting the butterflies themselves, as well as the pine and fir trees where the clump together for warmth.

“The severe drought we are experiencing is having effects,” Tavera said. “All the forests in the reserve are under water stress, the forests are dry.”

“The butterflies are looking for water on the lower slopes, near the houses,” she noted.

Tavera also expressed concern about the sever winter storms in Texas, which the butterflies will have to cross – and feed and lay their eggs – on their way back to their northern summer homes in coming months.

Tree full of Monarch butterflies at the Rosario Sanctuary, Michoacan, Mexico. Photograph: Brian Overcast/Alamy Stock Photo

“This is a cause for worry,” Tavera said, referring to whether the monarchs will find enough food and habitat after the winter freeze.

It was also a bad year for the mountain farming communities that depend for part of their income on tourists who visit the reserves. Because of the coronavirus pandemic, visits fell from around 490,000 last year, to just 80,000 in the 2020-21 season.

It was unclear whether the drop in tourism income contributed to the increased logging. Rickards said there has long been pressure on the area’s forests from people who want to open land for planting crops.

Felipe Martínez Meza, director of the butterfly reserve, said there have been attempts to plant orchards of avocados – a hugely profitable crop for farmers in the area – in the buffer zones around the reserve.

The high mountain peaks where the butterflies clump in trees are probably a bit above the altitude where avocado trees like to grow, Martinez Meza said. But the buffer zones provide protection and support for the higher areas, and he said more must be done to combat the change in land use.

Frequently, illegal logging is carried out by outsiders or organized gangs, and not by the farm communities that technically own the land.

Millions of monarchs migrate from the US and Canada each year to forests west of Mexico’s capital. The butterflies hit a low of just 0.67 hectares (1.66 acres) in 2013-14.

Loss of habitat, especially the milkweed where the monarchs lay their eggs, pesticide and herbicide use, as well the climate crisis, all pose threats to the species’ migration.

Saving the Butterfly Forest

The New Yorker

Environmental destruction and violence threaten one of the world’s most extraordinary insect migrations.

The New Yorker – Brendan George Ko

Photography by Brendan George Ko

Text by Carolyn KormannFebruary 8, 2021

Every November, around the Day of the Dead, millions of monarch butterflies descend on a forest of oyamel firs in the mountains of central Mexico. The butterflies have never seen the forest before, but they know—perhaps through an inner compass—that this is where they belong. They leave Canada and the northeastern United States in late summer and fly for two months, as far as three thousand miles south and west across the continent. The journey is the most evolutionarily advanced migration of any known butterfly, perhaps of any known insect. But climate change and habitat loss, both in the forest (photographed here in February last year) and in the U.S., are fast eroding the monarchs’ numbers.

Turn Volume On Icon
Click to unmute and listen
to the butterflies as you read.

Monarchs take flight as the sun rises
and begins to warm them up.
Once the sun sets, the butterflies
cluster in the oyamel-fir trees until
the next morning.

A pair of monarchs mating.
Soon they will migrate, and
the fertilized eggs will be laid
en route, spawning a new
generation to continue the journey.

Monarchs in the early morning.
They hibernate from November
until the beginning of March.
With warmer temperatures, they
become sexually mature, mate, and
begin their northerly migration. 

The Monarch Butterfly Biosphere Reserve, a partnership between the Mexican government and the World Wildlife Fund, is a hundred-and-thirty-nine-thousand-acre area, straddling the border between the states of Mexico and Michoacán, sixty miles northwest of Mexico City. The monarchs hibernate here, at an altitude of around ten thousand feet, for four months. The reserve comprises land belonging to dozens of groups, including indigenous communities and communal-land villages called ejidos. Before the reserve was founded, locals relied on logging and mining for income. Now they also get revenue from roughly a hundred and twenty thousand tourists who visit the reserve each year.

Angangueo, Michoacán, a
town situated halfway
between the two most visited
butterfly sanctuaries.

Roughly a hundred and twenty thousand
tourists visit the reserve each year, diversifying
the income of local communities, which
previously relied on logging and mining.

Michoacán is a battleground for drug cartels, whose activities extend to land theft and the lucrative timber trade. In January of last year, Homero Gómez González, a former logger who had become the supervisor at El Rosario, the most visited butterfly colony in the reserve, disappeared after attending a festival in the nearby city of Ocampo. Two weeks later, he was found drowned, with blunt-force injuries to the head, at the bottom of an irrigation pond. Then a tour guide who worked for him was found dead. Authorities reported that the deaths were under investigation, but most people are afraid to speak up.

While in Mexico, the monarchs look
for water but do not feed, relying on fat stores
accumulated in the course of migration.

The W.W.F. monitors the reserve’s forest cover each year, and issues checks to local communities based on their performance. Since 2005, thirty-seven thousand acres have been replanted. According to Eduardo Rendón-Salinas, the head of the W.W.F. monarch program in Mexico, the two communities that have pursued conservation most strictly, keeping timber harvests minimal and sustainable, “have the most beautiful forests in all of the reserve.” But the sense of heightened danger makes already challenging work much harder. Workers, including those at other local conservation-minded projects—thirty-four mushroom greenhouses, a trout farm, and thirteen tree nurseries—are scared.

Oyamel firs grow at between
nine thousand and eleven thousand
feet above sea level.

Pablo Angeles Hernández,
a forest engineer at the Monarch
Butterfly Biosphere Reserve.
Marciano Solis Sacarias,
a landowner, working at
Las Novias del Sol,
a tree-nursery coöperative.

Despite the reforesting efforts, the monarchs’ migration remains in grave danger. Last winter, the area they covered in the reserve decreased by fifty-three per cent, probably because the previous spring in Texas, the first main stop on the journey north and where they start laying eggs, was unusually chilly. The monarchs go through around four generations during their northward migration, each living four to five weeks; cooler temperatures limited the growth of milkweed, the only plant on which they lay their eggs, and slowed the growth of caterpillars—all of which made later generations smaller. The journey back to Mexico, in late summer, is accomplished in a single generation—known as the Methuselah generation, because its butterflies live for eight months.

In the coolness of the forest, the monarchs hang from the trees without moving or using any energy. It is only when direct sunlight warms them that they flutter to life.

The forest of oyamel firs
at El Rosario.

The microclimate of the forest is also changing. Violent storms, high temperatures, and dry conditions have disrupted the equilibrium on which the monarchs depend. Weak, parched trees succumb to bark beetles and other pests. A forest geneticist, Cuauhtémoc Sáenz-Romero, has experimented with planting oyamel firs farther up the mountains. It seems that the trees can survive a decrease in temperature of two degrees Celsius, the equivalent of being planted four hundred metres higher. The monarchs, however, are already near the top of the mountains, so Sáenz-Romero is looking to plant oyamel-fir groves on higher peaks, outside the reserve. These would be far from where the monarchs have ever been. Even if the planting is successful, will the butterflies find them?

Published in the print edition of the February 15 & 22, 2021, issue, with the headline “The Butterfly Forest.”

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