Monarch Butterfly Population Is Dangerously Low in California

Jennifer Hodges
January 24, 2020 - 1:41 pm
Monarch butterfly lifts off after drinking water January 29, 2001 at the butterfly sanctuary in Michoacan, Mexico.

Susana Gonzalez/Newsmakers

Western monarch butterflies face extinction, as their numbers remain dangerously low in California, despite efforts to help them recover. 

The large, orange butterfly with white and black spots draws an annual crowd at Natural Bridges State Park in Santa Cruz County during the species' migration. 

But only a little more than 29,000 monarchs were counted at 240 sites in late 2019, compared to the 1.2 million butterflies that wintered in California in 1997.

“They’re beautiful. They’re the main migrating butterfly,” said ranger Kate Brandon, who is stationed at Natural Bridges. “And if we take them out, we take them out.”

The monarch population has reached a historic low for the second year in a row. While weather and climate change play a role in the decline, Brandon said a loss in milkweed stands as a main concern. The butterflies commonly use the plant to lay their eggs.

But Brandon said there are ways to help reverse the decline.

“We encourage people to plant (milkweed) in San Jose and in the valleys, because when they leave here, part of their migration pattern is to go that way,” Brandon said.