Monarch Butterflies Will Go Extinct if We Don't Take Action Now - Treehugger

Monarch butterflies perform one of the most mind-bending feats in the animal kingdom. Weighing just half a gram, they fly on wafer-thin wings through cities and across interstates, migrating up to 2,800 miles from Canada and the United States to their wintering grounds in the forests of Mexico.

They grace our gardens with delight along the way and perform pollinating services that include contributions to healthy ecosystems and support for agricultural food production.

Yet they have been in perilous decline over the years—and despite the efforts of many, without more people getting on board, we run the risk of losing them altogether.

"In just one year, the presence of monarch butterflies in their wintering grounds [in Mexico] dropped 22%, from 7 acres to nearly 5.5. acres. This is part of a mostly downward trend over the past 25 years—when monarchs once covered more than 45 acres of forest," reports World Wildlife Fund (WWF).

Eastern Vs. Western Monarch Butterflies

The U.S. sees two types of migrating monarch butterflies, those in the east that fly from Canada to Mexico and those in the west that migrate down the Pacific coast to winter in California. It was long believed that the eastern and western monarchs were genetically distinct populations. But now scientists have confirmed that they are genetically the same. The journal Molecular Ecology published the findings, led by evolutionary biologists at Emory University.

This is just one of the findings from WWF-Mexico and Mexico's National Commission of Natural Protected Areas' annual monarch count. They have released two new reports related to the population and winter habitat of the Eastern migratory monarch butterfly, explains WWF. "The first shows a continued population decline and the second report highlights increased forest degradation where most monarchs cluster in colonies during the winter." From WWF:

The yearly WWF-Mexico-led survey, "Forest Area Occupied by Monarch Butterflies Colonies in Mexico," measures the area of forest in which monarch butterflies hibernate each winter, providing a scientific indicator of their population status. The 2022-2023 report shows a 22% decline in forest area when compared to last year, down from 7.02 acres to 5.46 acres this winter.

The second report, "Forest Degradation at the Core Zone of the Monarch Butterfly Biosphere Reserv," found 145 acres of forest have been degraded, a major increase when compared to the 47 acres lost in the previous year.

"Despite heroic efforts to save monarchs by planting milkweed, we could still lose these extraordinary butterflies by not taking bolder action," said Tierra Curry, a senior scientist at the Center for Biological Diversity, in a letter sent to Treehugger. "Monarchs were once incredibly common. Now they're the face of the extinction crisis as U.S. populations crash amid habitat loss and the climate meltdown."

Threats to the Monarchs

As explained by the International Union for Conservation of Nature (IUCN), which placed monarchs on the Endangered—Red List in 2022: "Legal and illegal logging and deforestation to make space for agriculture and urban development has already destroyed substantial areas of the butterflies' winter shelter in Mexico and California, while pesticides and herbicides used in intensive agriculture across the range kill butterflies and milkweed, the host plant that the larvae of the monarch butterfly feed on."

In the U.S., the butterflies have lost around 165 million acres of breeding habitat to herbicide spraying and development in the last few decades. "The caterpillars only eat milkweed, but the plant has been devastated by increased herbicide spraying in conjunction with corn and soybean crops that have been genetically engineered to tolerate direct spraying. The butterflies are also threatened by neonicotinoid insecticides, fungicides, and other chemicals that are toxic to young caterpillars," notes the Center for Food Safety (CFS). In 2014, scientists led by the Center for Biological Diversity and CFS petitioned the Fish and Wildlife Service to protect the butterfly under the Endangered Species Act.

According to WWF, the dwindling numbers leave the butterfly "highly vulnerable to extinction."

"It is not just about conserving a species, it's also about conserving a unique migratory phenomenon in nature," said WWF-Mexico's General Director Jorge Rickards. "Monarchs contribute to healthy and diverse terrestrial ecosystems across North America as they carry pollen from one plant to another. With 80% of agricultural food production depending on pollinators like monarchs, when people help the species, we are also helping ourselves."

According to CFS. the total number of monarchs is "64% below the minimum threshold scientists say is necessary for the migrating pollinators to not be at risk of extinction in North America. Monarchs east of the Rocky Mountains have declined by around 90% since the mid-1990s."

"We petitioned for protection for monarchs nine years ago, but they still face an onslaught of pesticides and habitat loss," said George Kimbrell, legal director at CFS. "This year's count shows once again that they continue to urgently need Endangered Species Act protection. The Fish and Wildlife Service has already agreed to make a final decision; now they only need make the correct one, the one conservation, science and the law requires: protect monarchs."

What Can We Do to Help the Butterflies?

Migrating Monarch butterflies in Monterey Bay, California. milehightraveler / Getty Images

Anna Walker, part of the IUCN SSC Butterfly and Moth Specialist Group and Species Survival Officer at the New Mexico BioPark Society, acknowledges the dire nature of the situation but believes there is still time. "It is difficult to watch monarch butterflies and their extraordinary migration teeter on the edge of collapse, but there are signs of hope. So many people and organizations have come together to try and protect this butterfly and its habitats. 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 making sure this iconic insect makes a full recovery."

Here are few things we ordinary citizens can do.

Stay Informed

Monarchs are currently on the candidate waiting list for Endangered Species Act protection. The U.S. Fish and Wildlife Service has a 2024 deadline to make a final listing determination. You can follow along here:

And don't forget: During elections large and small, VOTE for candidates who value biodiversity.

Be Careful with Pesticides

Monarch declines have been linked to the use of herbicides like Roundup, which kills milkweed. But pesticides are directly deadly—they are designed to kill insects, after all. For example, neonicitinoids are a class of broad-spectrum insecticides commonly used on farms, as well as around our homes, schools, and city landscapes. They are systemic and work by being absorbed by plants, making the entire plant toxic to insects that feed on it, including pollinators such as bees and butterflies.

There are so many other ways to deal with pest insects in your garden, ways that don't kill endangered butterflies.

Create a Butterfly Friendly Habitat

Plant Your Own Milkweed and Native Plants

As mentioned previously, monarch butterflies depend on milkweed. About 30 species of the plant are the only places where North American monarchs lay their eggs, and once those eggs hatch, milkweed serves as the exclusive food source for the caterpillars. With the destruction of so much milkweed, gardeners everywhere are encouraged to plant their own. It may seem futile given the scale of the problem—but imagine all of the lawns and gardens across North America and all that potential room for milkweed!

Visit the National Wildlife Federation's Garden for Wildlife for native plant collections that can be searched by area, including many plants that are especially helpful for monarchs.