Fewer Than 1% Left: Monarch Butterflies Are Facing Irreversible Extinction

Each year, monarch butterflies flock to California for the winter, spending their time in over 300 forested groves. The butterflies are typically spotted between November and March. Sadly, your chance of seeing one is getting smaller and smaller.

There was a time when you could easily spot a sea of these majestic black and orange pollinating butterflies, all the way from Baja California Peninsula to California’s Central Coast. As of today, populations are in steep decline and the future of this monarch species is in jeopardy.

To give you an idea as to how steep the decline in monarch butterflies is, picture this: in the 1980s, there were 4.5 million monarch butterflies in the world. Last year, there were just 28,429 monarch butterflies left. 


That’s a 99.4% population decline. Imagine if 90% of the people you knew were suddenly non-existent.

It’s “mind boggling,” said Emma Pelton, a conservation biologist at Xerces Society who spoke with the San Francisco Chronicle.

Xerces Society is the science-based nonprofit organization behind the study that uncovered just how quickly monarch butterflies are vanishing. Their goal is to protect invertebrates along with their habitats.

“We’re now down below 1 percent of the historic population,” said Pelton. 


Pelton explained the pending doom this presents for other species. The death of one monarch species could produce a domino effect regarding other insects and bird species. 

The loss of monarchs will present challenges for other insects, like bees – who are already in danger, as well as bird species that survive by eating insects. 

“It is very apt to say this is a canary in a coal mine for a lot of our native pollinators … There’s a tight link in a loss of insects and our songbirds, which rely on insects. We have declines in songbirds, and I think that links directly to declines in insects.

Emma Pelton, Conservation Biologist at Xerces Society

So, why are so many monarch butterflies vanishing? Scientists are hard at work trying to find the answer to this million-dollar question. So far, they’ve identified several factors that are likely involved – all of which relate to human economic activities. 

Contributing factors include: 

  • Logging 
  • Wide spread urbanization 
  • The use of pesticides and herbicides for corn and soybean crops 
  • The plowing of monarch’s milkweed habitat, which follows the route the butterflies migrate along
  • Increases in carbon dioxide

Furthermore, the University of Michigan published the results of an experiment that showed high carbon dioxide levels cause a reduction in a natural toxin produced by milkweed. 

Monarch caterpillars rely on this toxin to fight off parasites. In fact, researchers noted the butterflies were 77% less tolerant of parasites when they hatched on milkweed grown exposed to high levels of carbon dioxide. 

Carbon dioxide comes from emissions produced by cars and factories. This is what scientists consider the primary factor influencing climate change.  

The Xerces Society worked with hundreds of volunteers on Thanksgiving Day to count butterflies across 213 locations in California. Locations included forested groves in Santa Cruz, Pismo Beach, Fremont, and locations throughout Los Angeles, Riverside, and Monterey. 

The conservationist group has used the same method to collect monarch population records for decades. Below, you can see their records dating back to 1997, when they counted 1.26 million monarch butterflies.


Scientists knew the western monarch was in terrible, but they didn’t realize just how bad it was until “there was this other order of magnitude drop,” as Pelton described it. 

By the mid-2000s, there were just under 100,000 monarch butterflies. Considering now, a relatively short time later, there are only 28,000 left, that means we’ve lost a lot of butterflies each year. 

Unfortunately, as of now, it appears that they are headed for an “extinction vortex,” in which a species cannot naturally replenish their numbers. 


In the mid-20thcentury, scientists believe we entered a new era known as “Anthropocene,” in which humans control the future of Earth and are the main contributor to primary geological forces. 

The name “Anthropocene” comes from the combination of two Greek words: anthropos (human) and kainos (new). This man-made era is unlike anything before, although it has led to mass extinction for many plants and animals.   

If humans really do have the power to control the fate of our planet, that means we can still save these beautiful butterflies from complete extinction. But we better act fast because we are rapidly running out of time. 

Leave a Reply

Close Menu