The iconic migratory monarch butterfly, distinguished by its easily recognizable black-and-orange color palette, is now listed as endangered and could become extinct without further action to halt climate change and restore its habitats.
The International Union for Conservation of Nature (IUCN), a Switzerland-based conservation organization that monitors the status of wildlife, added migratory monarchs (Danaus plexippus plexippus) to its list of threatened species this week. The IUCN Red List now includes more than 41,000 species facing extinction.
The U.S. Fish and Wildlife Service, which helps implement the Endangered Species Act, meanwhile, has listed the monarch as a candidate for inclusion on its list of endangered and threatened wildlife since December 2020.
“Few species evoke the awe and wonder that the migratory monarch butterfly commands,” Sean T. O’Brien, who leads the nonprofit conservation group Nature Serve, says in a statement. “While efforts to protect this species are encouraging, much is still needed to ensure its long-term survival.”
Monarchs are not only beautiful pollinators, but they’re also unique: They’re the only known butterflies that make a two-way migration like birds do, per the U.S. Forest Service. Monarchs in eastern North America head south to Mexico’s Sierra Madre mountains, while those living in the west head to California’s mild coastal regions. In the summer, the butterflies return to locations throughout the United States and Canada to breed.
Populations of migratory monarchs, a subspecies of the monarch butterfly, have declined between 22 and 72 percent over the past ten years, according to a new assessment by the IUCN, because of pesticides and herbicides, as well as deforestation for logging, urban development and agricultural expansion. Human-caused climate change—in the form of drought, wildfire and extreme temperatures—is also threatening milkweed, the only plant monarch larvae feed on. Severe weather events have also killed off millions of monarchs, per the IUCN.
The western monarch population faces the biggest risk of extinction: Its population has dropped by an estimated 99.9 percent over the past 40 years, from ten million in the 1980s to 1,914 in 2021. Experts are concerned that not enough butterflies remain to keep the population alive.
But there’s still hope. To help boost monarch numbers, scientists and conservationists recommend planting more milkweed and nectar flowers, maintaining forests and limiting the use of pesticides and herbicides in the butterflies’ range, report CNN’s Madeline Holcombe and Jalen Beckford.
“People recognize the monarch,” Anna Walker, an entomologist at the New Mexico BioPark Society who led the assessment, tells the Washington Post’s Dino Grandoni. “People love the monarch. So that gives us an opportunity to do the outreach and get people on board.”
The IUCN also updated the status of several other species. The Yangtze sturgeon (Acipenser dabryanus) is now listed as extinct in the wild and 17 other sturgeon species are now recognized as critically endangered. The Chinese paddlefish (Psephurus gladius) is now extinct.
But the IUCN’s announcement wasn’t all bad news: Endangered tiger numbers are increasing, with a 40 percent uptick since 2015. Part of the increase can be explained by better monitoring efforts, but their population appears to be stable or increasing.