WASHINGTON (AP) — 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.
“It’s just a devastating decline,” said Stuart Pimm, an ecologist at Duke University who was not involved in the new listing. “This is one of the most recognizable butterflies in the world.”
The International Union for the Conservation of Nature (IUCN) 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.
The 2020 Species Status Assessment (SSA) mentions milkweed is essential to the survival of monarch butterflies. In arid climates, it can serve as the main nectar, oviposition and larval feeding resource for monarchs. The SSA found monarch butterflies are more vulnerable to catastrophic events than the species was historically known for.
IUCN attributes the insect's recent decline to habitat destruction and climate change. "To preserve the rich diversity of nature we need effective, fairly governed, protected and conserved areas, alongside decisive action to tackle climate change and restore ecosystems," said Dr. Bruno Oberle, IUCN Director General.
“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, who was not directly involved in the listing, 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.
Monarch butterflies in Idaho
The insect is unique for its genetically and ecologically different eastern and western populations divided by the Rocky Mountains, according to the Idaho Governor's Office of Species Conservation. Western monarchs migrate through Idaho to the California coast in the fall and depend on a variety of roosting trees, nectar, and milkweed resources. In contrast, the much larger eastern population usually found east of the Rocky Mountains migrates to high elevation fir forest in central Mexico, according to Idaho Fish & Game.
Idaho is part of the Western Monarch Butterfly Conservation Plan, which includes goals and strategies to help protect monarch butterflies such as:
- Overwintering
- Breeding habitat conservation
- Education and outreach
- Research and monitoring needs
