The brilliantly colorful and majestic Monarch butterfly is a true wonder of the world and American icon. Weighing less than a dime, the Monarch travels an astonishing 3,000 miles during its migration — a journey that traverses three countries and requires multiple Monarch generations to complete.
Sadly, over the last two decades, the Monarch butterfly’s overall population has declined by more than 90 percent — leaving the species at serious risk of extinction. Eastern Monarchs have declined by around 90 percent since the 1990s — while the Western Monarch population has dropped a jaw-dropping 99.5 percent.
The Western Monarch population, which winters in coastal California, saw a stunning decline from around 1.2 million in 1997 to fewer than 30,000 in 2019 — with preliminary results from 2020 surveys indicating further decline. Eastern Monarchs cluster in a small area in Mexico, and this population fell from more than 384 million in 1996 to fewer than 60 million in 2019. In 2013, those numbers dipped to an on-record low of 14 million
The primary drivers affecting the health of the two North American migratory Monarch populations are continued exposure to insecticides, effects of climate change, changes in breeding, migratory and overwintering habitat — due to conversion of grasslands to agriculture, urban development, widespread herbicide use, drought and more. Milkweed, the sole source of food for Monarch caterpillars and the only acceptable home for adult Monarchs’ eggs, has also declined across much of the butterfly’s range.
In the closing days of 2020, the U.S. Fish and Wildlife Service announced that listing the Monarch as endangered or threatened under the Endangered Species Act is warranted. The announcement came on the heels of a team of biologists’ extensive, peer-reviewed report that assessed the Monarch’s current and future status. The team also developed the Monarch Conservation Database to collect data on existing and future conservation efforts on behalf of the Monarch.
Today’s dwindling Monarch populations can benefit dramatically from widespread, ongoing conservation measures that help reduce threats and save the species — from the smallest of gardens to large, landscape-scale efforts. Every bit helps. Time is of the essence. Your contribution is needed.