Monarch Butterflies Added To Endangered List

Topline

The migratory monarch butterfly is the newest member of the endangered species list, as dwindling numbers accelerated by climate change, overdevelopment and pesticide use bring the iconic insect closer to extinction.

The migratory monarch butterfly was added to the IUCN’s endangered species list Thursday, as its … [+] North American population dwindles.

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Key Facts

The International Union for the Conservation of Nature, which makes the classification, lists habitat destruction from logging and deforestation, urban development in the butterfly’s wintering grounds on both coasts of the U.S. and in Canada, as well as agricultural pesticide use that kills monarchs and milkweed, the only plant monarch caterpillars eat, as the primary reasons behind the drop.

The group estimates its population dropped between 23% and 72% over the past 10 years, an unusually wide margin of error that it attributed to differences in study methods.

Climate change and changing weather patterns are also bringing the monarch, a crucial pollinator of plant habitats from Canada to Mexico, closer to extinction, as drought limits the growth of milkweed and increases the frequency of wildfires, and higher temperatures trigger earlier migrations before milkweed is available, the IUCN found.

The designation comes one month after a surprising study in the journal Global Change Biology found monarchs in parts of North America are steady as a result of rebounding summer populations that are potentially offsetting a decline in the winter that’s been documented for decades.

Even with the glimmer of hope, the monarchs continue to suffer, the IUCN found, with an even more pronounced decline on the West Coast, where the population dropped from roughly 10 million in the 1980s to less than 2,000 last year, a 99.9% drop, while on the east coast, the population decline is closer to 84%.

Migratory monarch butterflies, a subspecies of the monarch butterfly known for their iconic orange and black color and twice-annual 4,000-mile migration across the continent, were considered threatened for decades, but had never before come under the IUCN’s red list, and are not protected under the United States Fish and Wildlife Service.

Key Background

Researchers for the past few decades have warned monarch butterflies populations are declining fast, bringing the species closer to the brink of extinction. A group of scientists in 2014 called the situation “grim,” as a result of declining milkweed, largely from increasing use of widely used industrial pesticides and herbicides like glyphosate, the active ingredient in products like Roundup and Rodeo. Another study from Iowa State University published six years later in Frontiers in Ecology and Evolution, came to a similar conclusion, finding the population decline cannot be attributed to a lack of success in migration, but the loss of milkweed habitat. Despite the population loss, the U.S. Fish and Wildlife Service repeatedly declined to consider it a protected species in 2020, finding the population decline warranted the classification, but deciding instead to focus efforts on “higher-priority” species.

Tangent

The IUCN on Monday also released new figures showing a rapid decline in 26 species of sturgeons — the saltwater and freshwater fish whose eggs are used for caviar — while endangered white tiger numbers are stabilizing at roughly 3,726 to 5,578, 40% higher than 2015 estimates.

Crucial Quote

“Few species evoke the awe and wonder that the migratory monarch butterfly commands,” Nature Serve CEO Sean O’Brien said in a statement with the IUCN. “While efforts to protect this species are encouraging, much is still needed to ensure its long-term survival.”

What To Watch For

Whether the Fish and Wildlife Service considers monarchs protected under the Endangered Species Act, which opens the door for federal grants aimed at helping the species recover.