We were thrilled when some good news about one of the planet’s most beloved pollinators recently winged its way to us: The eastern monarch butterfly population nearly doubled over the past year, according to a new survey by World Wildlife Fund!
“Endangered” Classification Offers Hope for Monarch Population
In 2022, the migratory monarch butterfly was classified as “Endangered” by the International Union for Conservation of Nature (IUCN).
While that might sound disheartening, strangely enough, it may have been one of the best things that could have happened to Danaus plexippus, a tiny, spotted powerhouse that travels nearly 3,000 miles from the northern United States and southern Canada to its overwintering destination in the Highlands of Central Mexico.
Every year, millions of golden-orange monarchs gather to rest and mate in the oyamel fir forests before migrating back to the states, where they lay their eggs on the milkweed plants that serve as a food source for the caterpillars.
Although monarch populations have been in decline for years, it was only after the monarch was classified as “Endangered,” that the governments of Canada, the United States and Mexico finally had the scientific backing to collaborate with conservation organizations and the private sector on initiatives designed to restore, conserve and sustainably manage the ecosystems of this emblematic pollinator.
Monarch Numbers on the Rise in Mexico
The new survey , which measures the area of forest occupied by monarchs within the Monarch Butterfly Biosphere Reserve during the last two weeks of December, is implemented every year by WWF-Mexico and Mexico’s National Commission of Protected Natural Areas in collaboration with local communities.
Court Whelan
The monarch population wintering in central Mexico’s forests this year occupied 4.42 acres, up from 2.22 acres during the previous winter. This could be due to less severe drought than in previous years along the butterflies’ migration route.
Another potential supporting factor: Forest degradation in the core zone of the Monarch Butterfly Biosphere Reserve recently decreased by 10%. Between April 2023 and February 2024, 9.14 acres of forest were damaged. While that might not sound like good news, that was a decrease from the 10.13 acres of damage reported the previous year.
Forest degradation is most often caused by illegal logging, drought and the removal of trees to prevent disease spread. Monarchs require large, healthy forests to help protect them from winds, rain and low nighttime temperatures.
Monarch Population Trends Over Time
Court Whelan, a NatHab expedition leader with a PhD in both ecotourism and entomology and the author of The Monarch Migration: A Journey through the Monarch Butterfly’s Winter Home, says the population boom was promising. However, it will take more time to understand the greater trend.
“The big difference is that the new WWF monarch numbers are comparing only two years: the 2023/24 season to the 2024/25 migratory season,” he says. “But if you were to compare since 2000, the area monarchs occupy is down from 44 acres to 4 acres. So, while they’re up this year from roughly 2 acres to 4 acres, that’s still a big decrease over 25 years.”
Court Whelan
The news underscores the importance of local protection of butterfly habitat, says Jorge Rickards, director general of WWF Mexico.
“We recognize the key role of local communities, as well as the support of the government of Mexico in conserving the forest and providing this iconic species with the opportunity to thrive,” he says. “It’s now time to turn this year’s increase into a lasting trend with an all-hands approach where governments, landowners, conservationists, and citizens continue to safeguard critical habitats along the monarch’s North American migratory route.”
Now that this year’s numbers are in, scientists will analyze the increase and try to understand the correlation and causation behind it. Those results can inform and drive future conservation actions.
“We’re basically trying to understand what efforts pack the biggest bang for our buck in terms of research and conservation initiatives both old and new,” Whelan explains.
Current Threats to Monarch Butterflies
Although the annual monarch population in Mexico has increased, these beloved butterflies still face many threats. Most of their challenges are related to milkweed, the only plant in which the butterflies lay their eggs and from which monarch caterpillars feed. Climatic variations great impact the abundance of milkweed. Land-use changes in the United States, combined with the widespread use of herbicides and insecticides, also create a massive decline of milkweed.
Unfortunately, although this year held positive news for the monarchs, other butterfly species haven’t fared well, also largely because of insecticide use, climate change and loss of habitat. In the United States, the number of butterflies overall is down 22% since 2000, with populations in the Lower 48 states falling on average 1.3% a year since the turn of the century.
Nick Haddad, an entomologist at Michigan State University, says that while the annual rate of decline may not sound significant, it becomes “catastrophic and saddening” when compounded over time. “In just 30 or 40 years we are talking about losing half the butterflies (and other insect life) over a continent,” Haddad says.
Currently in the U.S., 114 butterfly species show significant declines. For example, the red admiral population is down 44%, the American lady butterfly population decreased by 58%, and even the invasive white cabbage butterfly fell by 50%, according to Collin Edwards, a quantitative ecologist at the Washington Department of Fish and Wildlife.
What Can You Do to Help Protect Monarchs?
With 80% of agricultural food production dependent on pollinators like monarchs, protecting them is of utmost importance. Luckily, there are a few easy things you can do to help!
Plant Milkweed and Native Flowers
Intentionally planting in your yard is an ideal place to start. Native milkweed starts can be found at MonarchWatch.org and will give the adult butterflies a place to lay their eggs in the spring.
But don’t stop just at milkweed. An abundance of native flowers of all types in your yard won’t just beautify your yard—it will also help fuel the monarchs on their long trip back to Mexico in the fall.
Chuck Sevilla
Buy Local and Organic
Buying produce that was grown without the use of herbicides and pesticides incentivizes farmers to grow food in a way that supports natural habitat for the monarchs, rather than eliminating wildflowers across millions of acres of cropland.
Help Monitor Monarchs
You can also play your part as a citizen scientist by recording your sightings of milkweed and breeding monarchs at monarchmilkweedmapper.org.
See Monarchs Sustainably
If you want to truly immerse yourself in the world of butterflies, consider joining us on one of our upcoming Kingdom of the Monarch trips to the forested Central Highlands of Mexico. On both foot and horseback, you can access an oyamel fir tree forest in two different monarch reserves to experience what it’s like to be in the presence of literally millions of monarchs—so many that you can actually hear the beating of their vivid orange wings at times!
Court Whelan
Conservation travel helps demonstrate to locals that ecotourism can be a more viable and sustainable source of economic well-being than resource exploitation. Although you may not be able to change the world in every way you’d like, intentional actions like supporting causes that you’re passionate about can make a difference!
Explore Mexico’s Central Highlands to observe and help protect endangered monarch butterflies on Nat Hab’s Kingdom of the Monarchs adventure.
