Plunging Monarch Butterfly Population Seen With Increasing Alarm

by Juliette Goodrich and Molly McCrea

In Pacific Grove recently, visitors flocked to a sanctuary to witness a natural wonder: the world famous western monarch butterfly stops here to spend the winter. But this year, visitors and locals alike left disappointed.

"There were hardly any monarchs to be seen," said David Durbin from Novato.

"There are a couple flying around, " observed Dionne Loftus, visiting from the United Kingdom.

"Oh, extremely sad," exclaimed local resident James Borber as he surveyed the site.

About 40 years ago, in the Bay Area, KPIX 5 News filmed quite a different scene at the nearby Santa Cruz Sanctuary:  thousands of California monarchs looking like leaves, and hibernating in clusters on the eucalyptus trees.

That's not the case these days.

"You look at the tree behind us and they're four butterflies, where before this whole area was butterflies." exclaimed Borber.

What's going on?

"Monarchs as far as we can tell based on our very limited geographic coverage are in big trouble right now," said "butterfly guru" Art Shapiro, Professor of Evolution and Ecology at University of California, Davis.

In the 1980s, an estimated 4.5 million western monarchs overwintered along the California coast. At last count, taken during the 2018 annual Thanksgiving count, their population hit a record low - just 28,429 butterflies.

That's down 86 percent from 2017.

Nick Stong and Juan Govea with the Pacific Grove Museum of Natural History explained monarchs are not just beautiful, they're critically important. These colorful invertebrates pollinate the plants we eat, and serve as food for other animals, including wasps, and birds like the black-headed grosbeak and cardinal.

"They're an essential part of our ecosystem," said Govea.

"If monarchs are facing these challenges, a lot of other insects probably are too," added Stong.

Two new studies published in reputable journals provide good evidence that insects around the world have gone missing in a big way,

One study, published in the Proceedings of the National Academy of Sciences, found an alarming decline in insect biomass from 1976 to 2013 in a pristine tropical rainforest located in Puerto Rico. The team set both ground and canopy traps, and in addition performed sweep net samples.

The reports' author, Dr. Brad Lister, told KPIX 5 that researchers found a 97 percent average decrease in biomass in the ground traps; 76 percent average decrease in the biomass found in the canopy traps; and a 82 percent average decrease in the biomass when they swept through the rainforest with bigger, studier butterfly nets.

In the second study, published online in PLOS One, researchers in Krefeld, Germany found more than a 75 percent decline over 27 years in the biomass they collected from flying insects in more than 60 protected nature preserves.

These two studies have caused some alarm. Some call it "insect armageddon" and the data supports what many suspect.

"They all point in the same direction," said Shapiro. "Something big is happening."

Since 1972, Shapiro has monitored butterfly populations – 150 different species at 10 different sites across Central California along the Interstate 80 corridor.

Monarchs are among the butterflies that Shapiro and his team monitor at his sites. Last year, he did not see a single monarch egg or larva. "There weren't any, anywhere," he exclaimed. Across all of his sites, he spotted a grand total of 36 monarch butterflies.

As to what's behind the bug decline? "We do not know," Shapiro said.

There is no good hard evidence. But some factors are believed to play a role: pesticides, agricultural practices such as monoculture, population growth, urban sprawl, loss of habitat, and climate change.

"The monarch is the canary in the coal mine that's really pointing us towards a greater problem that we have to be aware of." said Chris Grinter, Collection Manager of Entomology with the California Academy of Sciences.

He showed KPIX 5 News a special collection, found in one of the academy's specimen drawers. The label on the drawer is sobering. It says "extinct."

"We have a few extinct species here including the Xerces Blue Butterfly," said Grinter, as he pulled out the drawer to show us the rare extinct species, a beautiful little butterfly with blue gossamer wings. The Xerces blue butterfly lived in the sands dunes of San Francisco in the Sunset District in the 1940s until urban development drove them to extinction, Grinter said.

He hopes the monarch never ends up in this drawer. "We can hope to learn from some of the mistakes in the past," said Grinter.

Shapiro says butterflies are survivors. They've been around for 35 million years and have shown they can adapt.

"The question is whether they will manage to survive, given the very rapid change we're seeing now and the extent to which we've modified the landscape," said Shapiro.

In 2014, the U.S. Department of Fish and Wildlife began looking into whether the monarch butterfly should fall under federal protection as a threatened species. By the end of June, the agency will issue its findings.

The Xerces Society believes the public can take steps to save the monarch. The nonprofit acknowledges that science is investigating why the monarch is in decline but in the meantime, said individuals can take action now to help .

Shapiro cautions that the action that is truly needed in light of the apparent worldwide loss in insects is global and that nations around the world may need to make some tough decisions, especially around the use of certain pesticides.