Quantcast

Monarch Butterfly Population Plummets in California

Animals
Monarch butterfly on swamp milkweed. Jim Hudgins / USFWS

The population of monarch butterflies that spend winter along the California coast dropped 86 percent since 2017, according to a recent count by the Xerces Society, an invertebrate conservation group.

Preliminary results from the Western Monarch Thanksgiving Count, an annual citizen science program, recorded less than 30,000 butterflies overwintering in California, a significant decline from the estimated 192,000 in 2017. The official numbers will be released later this month.


Emma Pelton, a Xerces Society endangered species conservation biologist, wrote in a blog post that the initial results are "disturbingly low" and perhaps "catastrophic."

"While overwintering populations naturally fluctuate, even by double digit percentages, the magnitude of this year's drop is of significant concern because the monarch population was already at a new low after the 97 percent decline it has experienced since the 1980s ( Schultz et al. 2017), leading to a situation which may be catastrophic for the western population," Pelton wrote.

The 30,000 butterflies counted is the average quasi-extinction population size—or "the number of adult butterflies needed to ensure persistence of the western monarch population," Pelton explained.

It is not yet clear why their numbers were so low in 2018, although prolonged drought, a late rainy season, as well as smoke and poor air quality caused by the region's devastating wildfires could be to blame, Pelton suggested.

The latest count adds to more bad news for the iconic species, whose numbers have precipitously declined.

"In my lifetime, the monarch population in California has gone from millions of butterflies to hundreds of thousands and now, possibly, mere tens of thousands," Pelton wrote, noting that one study estimated 4.5 million monarchs overwintering in California in the 1980s.

"Next year will be a real test in how resilient the western monarch population is, after its California overwintering population has been reduced to less than 0.5 percent of its historical size," she added.

Scientists warn that the black-and-orange butterflies—known for their annual, 3,000-mile migration from the U.S. and Canada to Mexico—is at risk of extinction.

Overall, the monarch population has dropped by more than 80 percent over the past two decades. Their disappearance has been linked to climate change, habitat loss, pesticides and reduced milkweed, a native wildflower and main food source for monarch caterpillars and the only plant on which adult monarchs lay their eggs.

Despite the grim report, there are ways you can help the survival of the beloved species, which are also crucial pollinators for many different kinds of wildflowers.

"While western monarchs are facing unprecedented challenges right now, there is still hope that we can recover the population if we work quickly, strategically and together," Pelton said.

Learn more about how you can help.

EcoWatch Daily Newsletter

Sam Cooper

By Sam Cooper

Thomas Edison once said, "I'd put my money on the sun and solar energy. What a source of power!"

Read More Show Less
A NOAA research vessel at a Taylor Energy production site in the Gulf of Mexico in September 2018. NOAA

The federal government is looking into the details from the longest running oil spill in U.S. history, and it's looking far worse than the oil rig owner let on, as The New York Times reported.

Read More Show Less
Sponsored

Zero Waste Kitchen Essentials

Simple swaps that cut down on kitchen trash.

Sponsored

By Kayla Robbins

Along with the bathroom, the kitchen is one of the most daunting areas to try and make zero waste.

Read More Show Less
Golde Wallingford submitted this photo of "Pure Joy" to EcoWatch's first photo contest. Golde Wallingford

EcoWatch is pleased to announce our third photo contest!

Read More Show Less
Damage at the Malheur National Wildlife Refuge from the 2016 occupation. USFWS

By Tara Lohan

When armed militants with a grudge against the federal government seized the Malheur National Wildlife Refuge in rural Oregon back in the winter of 2016, I remember avoiding the news coverage. Part of me wanted to know what was happening, but each report I read — as the occupation stretched from days to weeks and the destruction grew — made me so angry it was hard to keep reading.

Read More Show Less
Sponsored
Computer model projection of temperature anomalies across Europe on June 27. Temperature scale in °C. Tropicaltidbits.com

A searing heat wave has begun to spread across Europe, with Germany, France and Belgium experiencing extreme temperatures that are set to continue in the coming days.

Read More Show Less
Skull morphology of hybrid "narluga" whale. Nature / Mikkel Høegh Post

In the 1980s, a Greenlandic subsistence hunter shot and killed a whale with bizarre features unlike any he had ever seen before. He knew something was unique about it, so he left its abnormally large skull on top of his toolshed where it rested until a visiting professor happened upon it a few years later.

Read More Show Less
A house under construction with plastic bottles filled with sand to build shelters that better withstand the climate of the country where temperatures reach up to 50° C Awserd in the Saharawi refugee camp Dakhla on Dec. 31, 2018 in Tindouf, Algeria. Stefano Montesi / Corbis / Getty Images

A UN expert painted a bleak picture Tuesday of how the climate crisis could impact global inequality and human rights, leading to a "climate apartheid" in which the rich pay to flee the consequences while the rest are left behind.

Read More Show Less