Study finds 29,000 butterflies, compared with 4.5 million during the 1980s, as experts point to habitat destruction
The western monarch butterfly population wintering along California’s coast remains critically low for the second year in a row, a count by an environmental group released Thursday showed.
The count of the orange-and-black insects by the Xerces Society, a not-for-profit environmental organization that focuses on the conservation of invertebrates, recorded about 29,000 butterflies in its annual survey. That’s not much different than last year’s tally, when an all-time low 27,000 monarchs were counted.
“We had hoped that the western monarch population would have rebounded at least modestly, but unfortunately it has not,” said Emma Pelton, a monarch conservation expert with the Xerces Society.
By comparison, about 4.5 million monarch butterflies wintered in forested groves along the California coast in the 1980s. Scientists say the butterflies are at critically low levels in the Western US due to the destruction of their milkweed habitat along their migratory route as housing expands into their territory and use of pesticides and herbicides increases.
Researchers also have noted the effect of climate change. Along with farming, climate change is one of the main drivers of the monarch’s threatened extinction, disrupting an annual 3,000-mile migration synced to springtime and the blossoming of wildflowers.
“We think that it has to do with habitat loss, the increasing high use of pesticides and the loss of the milkweed populations, which is the plant the monarch needs to lay its eggs on,” Monroe said.
California’s coast, from Bolinas to Pismo Beach, is a popular overwintering site for the western population of monarch butterflies. Historically, you could find millions of the orange and black winged invertebrates around this time of year, using coastal eucalyptus trees as shelter.
But there’s been a troubling trend over the past few decades. Each year, fewer monarchs have been showing up to overwinter on the state’s coast, according to preliminary numbers from the Xerces Society, an environmental conservation nonprofit. The group’s annual Thanksgiving count found the 2018 population of these butterflies is down to 20,456 compared to 2017’s 148,000. That’s a one year, 86 percent decline.
“It’s been hard for me, as I remember the millions of monarchs of the 1980s,” said Mia Monroe, a Bay Area-based Xerces Society member who helps lead California’s monarch population count. “We only have less than one percent of the monarchs that we once historically had.”
Gaye LeBaron, THE PRESS DEMOCRAT
There was a wire service news story in the paper a couple of weeks ago about monarch butterflies.
It seems that in late October, some of the eastern monarchs, which are supposed to migrate south to Mexico each fall, were still hanging out in Canada’s Point Pelee National Park on a northern flank of Lake Erie. They should have been “on the road,” so to speak, at least six weeks earlier.
This is scary stuff for the lepidopterists who study butterflies and are already concerned about the effects of climate change on the insects.
Monarchs, they know, don’t do well when the temperature drops below 50 degrees — the muscles that make them flutter apparently stiffen in the cold.
Some consider this another reason to declare the big orange and black butterflies that are the undisputed sovereigns of the butterfly world an endangered species. Some will go further, taking this new glitch in the ecosystem as a warning that the apocalypse draws closer. The optimists say, let’s wait and see what happens next year before we panic.
I am not versed in lepidoptery or entomology. But I do know a little something about monarchs — western monarchs, that is — the ones who live west of the Rocky Mountains in both the U.S. and Canada.
Their southbound migration route hugs the Pacific Coast and can go all the way to Mexico every winter. They have a lot of choices, in California’s temperate coastal climes, as to where to spend their winters.
Read more at: Gaye LeBaron: Butterfly migration is a Thanksgiving tradition on Sonoma Coast
Winter is coming … later. And it’s leaving ever earlier.
Scientists say it is yet another sign of the changing climate, and that it has good and bad consequences for the nation. There could be more fruits and vegetables — and also more allergies and pests.
“I’m happy about it,” said Karen Duncan of Streator, Illinois. Her flowers are in bloom because she’s had no frost this year yet, just as she had none last year at this time either. On the other hand, she said just last week it was too hot and buggy to go out — in late October, near Chicago.
The trend of ever later first freezes appears to have started around 1980, according to an analysis by The Associated Press of data from 700 weather stations across the U.S. going back to 1895 compiled by Ken Kunkel, a meteorologist at the National Oceanic and Atmospheric Administration’s National Centers for Environmental Information.
Read more at: Science Says: Jack Frost nipping at your nose ever later
PRESS RELEASE: Center for Biological Diversity, Center for Food Safety, Xerces Society
In response to a petition by the Center for Biological Diversity, Center for Food Safety, Xerces Society and renowned monarch scientist Dr. Lincoln Brower, the U.S. Fish and Wildlife Service said today that Endangered Species Act protection may be warranted for monarch butterflies. The agency will now conduct a one-year status review on monarchs, which have declined by 90 percent in the past 20 years.
“The Endangered Species Act is the most powerful tool available to save North America’s monarchs, so I’m really happy that these amazing butterflies are a step closer to the protection they so desperately need,” said Tierra Curry, a senior scientist at the Center for Biological Diversity.
“Our petition is a scientific and legal blueprint for creating the protection that the monarch so direly needs, and we are gratified that the agency has now taken this vital first step in a timely fashion,” said George Kimbrell, Senior Attorney for Center for Food Safety. “We will continue to do everything we can to ensure monarchs are protected.”
“We are extremely pleased that the federal agency in charge of protecting our nation’s wildlife has recognized the dire situation of the monarch”, said Sarina Jepsen, the Xerces Society’s endangered species director. “Protection as a threatened species will enable extensive monarch habitat recovery on both public and private lands.”
The butterfly’s dramatic decline is being driven in large part by the widespread planting of genetically engineered crops in the Midwest, where most monarchs are born. The vast majority of genetically engineered crops are made to be resistant to Monsanto’s Roundup herbicide, a potent killer of milkweed, the monarch caterpillar’s only food. The dramatic surge in Roundup use with Roundup Ready crops has virtually wiped out milkweed plants in Midwestern corn and soybean fields. In the past 20 years it is estimated that these once-common iconic orange and black butterflies may have lost more than 165 million acres of habitat — an area about the size of Texas — including nearly a third of their summer breeding grounds.
The population has declined from a recorded high of approximately 1 billion butterflies in the mid-1990s to only 35 million butterflies last winter, the lowest number ever recorded. The overall population shows a steep and statistically significant decline of 90 percent over 20 years. In addition to herbicide use with genetically engineered crops, monarchs are also threatened by global climate change, drought and heat waves, other pesticides, urban sprawl and logging on their Mexican wintering grounds. Scientists have predicted that the monarch’s entire winter range in Mexico and large parts of its summer range in the states could become unsuitable due to changing temperatures and increased risk of drought, heat waves and severe storms.
Monarch butterflies are known for their spectacular multigenerational migration each year from Mexico to Canada and back. Found throughout the United States during the summer months, in winter most monarchs from east of the Rockies converge in the mountains of central Mexico, where they form tight clusters on just a few acres of trees. Most monarchs west of the Rockies migrate to trees along the California coast to overwinter.
The size of the overwintering population in Mexico is expected to be up this year due to favorable spring and summer weather, but even with the expected one-year population increase, the monarch population will only be a fraction of its historical size.
Monarchs need a very large population size to be resilient to threats from severe weather events and predation. Nearly half of the overwintering population in Mexico can be eaten by bird and mammal predators in any single winter; a single winter storm in 2002 killed an estimated 500 million monarchs — 14 times the size of the entire current population.
The Fish and Wildlife Service must next issue a “12-month finding” on the monarch petition that will propose protection under the Endangered Species Act, reject protection under the Act or add the butterfly to the candidate waiting list for protection.
via Monarch Butterfly Moves Toward Endangered Species Act Protection.