- The iconic monarch butterfly is designated as Endangered on the IUCN Red List of Threatened Species, which means it is likely to become extinct unless considerable intervention is taken.
- According to counts at overwintering locations in California and Mexico, the number of migratory monarch butterflies has decreased by more than 95 percent since the 1980s.
- The monarch decline is being driven by habitat loss, herbicide and pesticide use, logging at overwintering sites in Mexico, urban development, and drought. They are famous for their amazing migrations of more than 6,400 kilometers (4,000 miles) over numerous generations.
- According to experts, plating milkweed, lowering herbicides, and safeguarding overwintering places for butterflies are all necessary strategies to maintain this valued species.
The International Union for Protection of Nature (IUCN), a global authority on species conservation, has classified the famous monarch butterfly as Endangered. If a species is listed as endangered, it is likely to become extinct unless considerable intervention is taken.
It’s no surprise that migrating monarch butterflies (Danaus plexippus plexippus) have been added to the IUCN Red List of Threatened Species. Since the 1980s, the number of monarch butterflies has decreased by more than 95 percent. Scientists attribute the decline to climate change, habitat loss, and the usage of herbicides and pesticides.
“It’s been very terrible to see their numbers fall so significantly,” Karen Oberhauser, a conservation scientist at the University of Wisconsin who has studied monarch butterflies for more than three decades, told The New York Times.
Two populations of migratory monarch butterflies may be found in North America, and they are both renowned for making remarkable overland treks that can last up to 6,400 kilometers (4,000 miles). While the winter season for western monarchs is spent in California, it is spent in Mexico for eastern monarchs. Every monarch makes a northward migration in the spring, some even reaching Canada. Over the course of three or four generations, this migration cycle travels thousands of miles. At their wintering sites, monarch population estimations are made.
The eastern population, which makes up around 90% of migrating monarchs, has been dwindling for many years. For the purpose of calculating the population number, the monarchs’ wintering sites in Mexico are utilized as a proxy. According to these region estimates, the number of eastern monarchs peaked in 1996 at roughly 384 million and declined to about 60 million in 2019.
Western monarch populations that overwinter in California had a stunning resurgence this past winter. A very low 2,000 butterflies were counted in 2020, while more than 247,000 butterflies were in 2021. However, despite the fact that more than 1.2 million butterflies were counted in 1997, the population has still drastically decreased from historical levels.
The IUCN SSC Butterfly and Moth Specialist Group member Sophie Ledger said in a statement that it was heartbreaking to see one of the world’s most well-known butterfly species, with amazing migratory patterns and local cultural value, in danger of going extinct.
The U.S. Fish and Wildlife Service (USFWS) said in December 2020 that although monarchs met the requirements to be listed under the U.S. Endangered Species Act, the species would not be added because other species have a higher priority.
A California court decided in June 2022 that invertebrates, like as insects, can now be classified under the California Endangered Species Act (CESA), which may pave the way for the state-wide designation of Western monarch butterflies. If they were listed as endangered, their wintering grounds in California would be given legal protection.
In an email to Mongabay, Scott Hoffman Black, executive director of The Xerces Society for Invertebrate Conservation, said, “We have watched the numbers substantially fall over the years in our western monarch census and know this species needs our support.” The Xerces Society provided an expert review to the IUCN in support of the migratory monarch’s designation as endangered.
The loss and degradation of habitat caused by the conversion of grasslands to agriculture, the use of herbicides and insecticides, logging at overwintering locations in Mexico, urban development, and drought have an impact on monarch health.
According to a species status assessment report issued by the U.S. Fish and Wildlife Service in 2020, there is a 50–70% possibility that eastern monarch populations may reach the threshold at which extinction is unavoidable over the next 60 years. The likelihood of a western king is 60–68% within 10 years and 99% within 60 years. Extreme weather conditions and other catastrophic occurrences are not included in this estimation. Together with its partners, the USFWS says it will keep putting emphasis on conservation measures.
Black continued, “Fortunately, there is still time to take action, and we are inspired by the thousands of people who have made it their goal to save monarchs by growing milkweed and nectar flowers and safeguarding these insects from pesticides.
To attempt and safeguard this butterfly and its surroundings, so many people and organizations have banded together. We all have a part to play in ensuring that this iconic insect makes a full recovery, Anna Walker, a member of the IUCN SSC Butterfly and Moth Specialist Group who led the IUCN monarch butterfly assessment, said in a statement. “From planting native milkweed and reducing pesticide use to supporting the protection of overwintering sites and contributing to community science, we all have a role to play in ensuring this iconic insect makes a full recovery.
She continued, “It is heartbreaking to see monarch butterflies and their remarkable migration teeter on the brink of extinction, yet there are signals of hope.”