Monarch butterflies put on endangered list

The monarch butterfly fluttered a step closer to extinction Thursday, as scientists put the iconic orange-and-black insect on the endangered list because of its fast dwindling numbers.

The International Union for the Conservation of Nature added the migrating monarch butterfly for the first time to its “red list” of threatened species and categorized it as “endangered” — two steps from extinct.

The group estimates that the population of monarch butterflies in North America has declined between 22% and 72% over 10 years, depending on the measurement method.

“What we’re worried about is the rate of decline,” said Nick Haddad, a conservation biologist at Michigan State University. “It’s very easy to imagine how very quickly this butterfly could become even more imperiled.”

Haddad estimates that the population of monarch butterflies he studies in the eastern United States has declined between 85% and 95% since the 1990s.

In North America, millions of monarch butterflies undertake the longest migration of any insect species known to science.

After wintering in the mountains of central Mexico, the butterflies migrate to the north, breeding multiple generations along the way for thousands of miles. The offspring that reach southern Canada then begin the trip back to Mexico at the end of summer.

A smaller group spends winters in coastal California, then disperses in spring and summer across several states west of the Rocky Mountains. This population has seen an even more precipitous decline than the eastern monarchs, although there was a small bounce back last winter.

Emma Pelton of the nonprofit Xerces Society said the butterflies are imperiled by loss of habitat and increased use of herbicides and pesticides for agriculture, as well as climate change.

“There are things people can do to help,” she said, including planting milkweed, a plant that the caterpillars depend upon.

The United States has not listed monarch butterflies under the Endangered Species Act, but several environmental groups believe it should be listed.



Monarch butterflies land on branches at Monarch Grove Sanctuary in Pacific Grove, Calif., Wednesday, Nov. 10, 2021. On Thursday, July 21, 2022, the International Union for the Conservation of Nature said migrating monarch butterflies have moved closer to extinction in the past decade – prompting scientists to officially designate them as “endangered." (AP Photo/Nic Coury, File)