Spring has returned, and with it a glimmer of hope for one of North America’s favorite little creatures to spot fluttering in their gardens: the monarch butterfly.
Despite a long-term downward trend in the size of the eastern migratory monarch butterfly population, conservation efforts have led the orange-and-black winged insects to grow in numbers this season. New reports from the World Wildlife Foundation in Mexico and its partner organizations estimate a 64% increase in species population, as well as a significant decrease in forest degradation within monarchs’ winter habitats.
“It’s great that numbers appear to be up from last year and the previous year, but they are still really low,” says Lee Brown, who researches monarch butterflies and teaches biology at James Madison University.
Brown notes that animal populations – especially insects – fluctuate from year to year. “What happens one year to the next can be exciting when it’s not bad news. But we need to consider the long-term trends – which show an overall decline in monarch populations – and enact protections and conservation actions that help to mitigate these declines,” she says.
Eastern monarchs are known for their extraordinary annual voyage from the U.S. and Canada to Mexico at the end of the summer, where the forests of Michoacan and Estado de Mexico become their hibernation homes.
A WWF-led survey measuring the area of forest where monarch colonies hibernate each winter found that the butterflies occupied 7.24 acres of forest this 2025-26 winter, compared to 4.42 acres the previous winter.
For reference, the highest recorded area occupied by monarchs in Mexico was 44.95 acres of forest in the 1996-97 winter. The lowest was 1.66 acres in the 2013-14 winter.
One of the new reports cites the decrease of milkweed plants in monarchs’ North American breeding sites as a major threat to their population size.
“Milkweed is the only plant on which they’ll lay their eggs and the only source of food for baby monarch caterpillars,” said WWF podcast host Seth Larson in Tuesday’s episode of “Nature Breaking.”
“But milkweed has been vanishing across North America due to the use of herbicides and pesticides, as well as land-use change and other factors,” added Larson.
Planting more milkweed is a simple way to help conserve the monarch population.
“Millions of people have gotten involved in that in recent years, planting it in their yards, in their neighborhoods and their communities,” said Larson.
Extreme weather caused by climate change also affects the monarchs’ life cycle. Monarchs are highly sensitive to weather and climate, as they depend on environmental cues – such as temperature – to trigger reproduction, migration and hibernation.
Another new report found that significantly less forest degradation occurred in the Central Mexican forests where the monarchs hibernate between February 2024 and February 2025 compared to the previous year. Illegal logging, forest fires and droughts are the main drivers of this degradation.
Why should people care about conserving the monarch butterfly population? For one, monarchs are important pollinators and serve as a food source for many predators.
Brown explains that monarchs are considered a “flagship species” because “people love them and will invest in their protection over other less well-known pollinators.” Monarchs are also an “umbrella species” for pollinators, “because restoration of their habitat can help mitigate declines in other pollinator populations as well,” she says.
Just as valid are the cultural and educational importance of monarchs.
“They’re often the first insect kids learn about in school when they learn about insect life cycles,” Brown points out. A hallmark experience for many American kindergarten students is watching caterpillars transform into butterflies, then setting the beautiful monarchs free in the spring.
Monarchs are also special to Mexican culture, as the land’s Indigenous people believed the butterflies were the souls of their deceased ancestors returning each year for the Day of the Dead celebration.
So what should people make of this increase in the monarch population? Brown says, “We can be cautiously optimistic, but we still need protections for the species and to keep doing the hard work of minimizing habitat loss, pesticide use and impacts of climate change.”
