The monarch butterfly is the long-distance runner–or in this case, flier–of the insect world. No other butterflies migrate as far as the monarch of North America, which flies up to three thousand miles each year. Millions of these butterflies will fly from Mexico to Canada this spring, though populations in Florida don’t travel. Come autumn, they’ll return to overwintering sites in Mexico.
The entire trip takes four generations to complete. Yes, four generations of monarchs will be born, fly, mate and die during the annual migration. And somehow, they know exactly which trees their great-great-grandparents roosted upon in Mexico’s Oyamel forest.
But they’re on the decline. According to the Center for Biological Diversity, the monarch population has dropped 90% over the past 20 years. Scientists look to monarchs and other butterflies as indicators of environmental health, since they are easily affected by air and water pollution, climate change and the presence of toxins. When butterfly numbers drop, there’s a problem.
The World Wildlife Fund classifies the invertebrates as “near threatened,” which means they are “likely to become endangered in the near future.” The main problems facing monarchs are deforestation, severe weather and lack of milkweed, the primary food source for butterfly larvae.
However, scientists believe that the population can rebound if proper steps are taken. Butterflies rely on long swaths of blooming flowers as an energy supply for their long journey, which are called “nectar corridors.” Habitat management projects, like the ones supported by Monarch Watch, encourage citizens to plant milkweed in their gardens or yards, along with native plants as nectar supply. These “waystations” can even be certified through monarch conservation groups.
As a response to deforestation and illegal logging, the Mexican government protects 217 miles of forest for the Monarch Butterfly Biosphere Reserve. But everyday citizens can help, too. Conservation groups encourage people to look for Forest Stewardship Certified (FSC) lumber and furniture when shopping. This designation means the wood was taken in an environmentally responsible manner.
These small steps could make the difference in saving the species from extinction.
Monarchs drop to the ground during mating. Source: Learner
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Deforestation in Mexico has reduced the areas to which monarchs migrate and also opens the forests to cold air. Source: Amusing Planet
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Forested canopy acts as an umbrella and blanket for roosting monarchs, but exposure drops their internal temperature – they’re cold blooded – and can kill them. Source: Amusing Planet
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Mexico has worked to eliminate illegal logging, but more will have to be done. Authorities must enforce the laws designed to protect important habitat. Source: Amusing Planet
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Severe, dry weather in Texas and Mexico this past year has also had a negative impact on monarch populations. Extreme conditions diminish available food, water and shelter. Source: Wordpress
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Drought conditions not only ruin people’s gardens, they ruin butterfly food sources as well. Source: Blogspot
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Flowers disappear along the monarch’s flower highway, leaving them with no consumable nectar. Additionally, extreme weather conditions killed off the milkweed plants that are so vital to the monarch’s life cycle. Source: Creativity For The Soul
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The royal insects lay their larvae on native milkweed and it is the caterpillars’ primary food source. Source: Florida Native Nurseries
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The milkweed plant is the basis for all monarch butterfly reproduction and growth. Source: National Geographic
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The caterpillar consumes toxins from the milkweed that will make it bitter and poisonous, even in butterfly form. Source: National Geographic
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Milkweed grows rampant around crops and can stifle crop yield, so farmers use pesticides to kill it. A declination in milkweed means a declination in monarch populations. Source: Technology
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Conservation groups host events on building butterfly waystations and scientists are encouraging citizens to get involved. Source: Texas Butterfly Ranch
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By adding milkweed and nectar plants to gardens and yards, the monarchs will have habitat “drive-thrus,” where they can feed and deposit eggs. Source: Daily Mail
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Some monarch conservationists have had luck feeding caterpillars cucumber and pumpkin, but the monarch will not lay her eggs on these items during her migration. Source: Texas Butterfly Ranch
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The U.S. Fish and Wildlife Service has also pledged funds to help restore and protect monarch habitat, as the milkweed plant has decreased 21% since 1995. Source: Organic Authority
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We may not be able to stop severe weather conditions, but we can plant a few flowers to help. Source: Learner
John Kuroski is the editorial director of All That's Interesting. He graduated from New York University with a degree in history, earning a place in the Phi Alpha Theta honor society for history students. An editor at All That's Interesting since 2015, his areas of interest include modern history and true crime.
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Sims, Susan. "What’s Happening To Monarch Butterfly Migration?." AllThatsInteresting.com, April 28, 2015, https://allthatsinteresting.com/monarch-migration. Accessed February 12, 2025.