Monarch butterflies gather on a tree in central Mexico.

Sylvain Cordier/Biosphoto/Minden Pictures

Goodbye, Butterflies?

Monarch butterflies are disappearing. Is it too late to save the species?

Each spring, the California sky becomes a sea of orange and black. Thousands of monarch butterflies take flight in one of the world’s most famous migrations. The butterflies have spent the winter clustered in trees along the coast of California. Now, they’re migrating north, flying up to 100 miles a day.

However, fewer monarchs than ever are making that journey this year. In December, scientists announced that the number of monarchs in California was the lowest on record. It’s part of a trend that’s seen the monarch population plummet over the past 20 years.  

“The population was already not doing well, and then it took a nosedive,” says Emma Pelton. She is a scientist at the Xerces Society, a conservation group that tracks western monarchs. Pelton and other experts are worried that western monarchs may soon completely disappear.

Butterflies in a Bind

The butterflies’ long journey begins each fall. Monarchs in North America follow two main migration routes. Most fly south to Mexico, though those in the West mainly head to the California coast (see “Monarch Migration”).

Since the 1990s, however, the overall number of monarchs has dropped by hundreds of millions. Western monarchs are in the most trouble.

“We’ve lost about 99 percent of our monarchs in the West,” Pelton explains.

One reason is the loss of habitat in the areas where monarchs spend the winter. To make way for homes and farmland, people have cut down many of the trees where butterflies live.

However, the biggest threat to monarchs is the disappearance of a flowering plant called milkweed. It’s the only plant where they lay eggs, and monarch caterpillars eat only milkweed leaves.

But milkweed has become a lot harder to find in North America. Some farmers and homeowners spray chemicals called herbicides to kill weeds. These chemicals have also wiped out millions of acres of milkweed.  

Plus, wildfires and severe storms made it difficult for the butterflies to survive last year’s migration to California.

Jim McMahon/Mapman®

Fighting for a Future

The situation for monarchs is so dire that the U.S. Fish and Wildlife Service is considering adding them to the endangered species list. If that happens, the milkweed habitats along the butterflies’ migration routes would be protected by the government. The decision is expected in June.

Meanwhile, the Xerces Society is working with officials in the California towns where monarchs spend their winters. The group is replanting trees and working to prevent any more of the monarch habitats from being destroyed. It is also encouraging people along migration paths to plant milkweed. 

“Everybody should be helping,” Pelton says. “There are still butterflies, and they can bounce back.”

Illustration by Kate Francis

1. Who is Emma Pelton? Why is she mentioned in the article?

2. Explain the meaning of the subheading “Butterflies in a Bind.”

3. How are people working to help monarchs?

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