Monarch Butterfly Population Sees Significant Increase
The population of monarch butterflies in Mexico increased by 64% this winter compared to the same period in 2025, providing hope for a species considered at risk of extinction.
Data released this week by the World Wildlife Fund (WWF) Mexico indicated that the area occupied by monarchs expanded to 2.93 hectares (7.24 acres) of forest from 1.79 hectares (4.42 acres) the previous winter, marking the largest coverage since 2018.
“The monarch butterfly is the symbol of the trilateral relationship between Mexico, the United States and Canada,” Mexican environment minister Alicia Bárcena Ibarra said at a news conference on Tuesday. “Its conservation is a collective commitment we must maintain for the future.”
Migration and Threats to Monarch Butterflies
Every fall, tens of millions of monarch butterflies travel nearly 3,000 miles from Canada, across the United States, and finally to the forests of western Mexico. In these forests, the orange insects cover entire trees and flutter through the air in a spectacular display.
However, a combination of habitat loss due to deforestation, the climate crisis, and the use of herbicides has caused their numbers to decline significantly over the past 30 years.
In the United States, the increased use of herbicides such as glyphosate and dicamba has greatly reduced the availability of milkweed, the only plant monarch caterpillars can consume, leading to a sharp drop in butterfly populations.
Conservation Efforts and Legal Actions in the US
Due to this decline, the Biden administration proposed listing the monarch as threatened under the Endangered Species Act by the end of 2024. However, officials from the Trump administration have since delayed this decision indefinitely. In February, two environmental groups filed a lawsuit to compel the Trump administration to set a date for protections.
“It would be unforgivable for [the monarch’s] epic migrations to collapse because of political cowardice on enacting range-wide protections for them,” said Tierra Curry, endangered species co-director at the Center for Biological Diversity, one of the groups behind the lawsuit. “Even the Trump administration has to think twice about letting these iconic butterflies collapse toward oblivion.”
Challenges in Mexico’s Monarch Butterfly Habitat
In Mexico, illegal logging in the state of Michoacán has led to the loss of vast areas of forest, partly driven by organized crime groups involved in the lucrative avocado trade.
Compared to a peak of nearly 18.21 hectares (45 acres) in the winter of 1995, the area covered by monarchs in Mexico today is only a small fraction and remains well below the 6.07 hectares (15 acres) that scientists identify as necessary for the species’ survival.
The involvement of cartels in logging has sometimes resulted in violence: in 2020, Homero Gómez González, a prominent monarch butterfly conservator in Mexico, was found dead, with his family suspecting he was targeted due to his efforts to protect the monarch’s habitat.
Progress in Conservation and Forest Protection
Despite these challenges, conservation efforts have reduced logging in recent years. From a peak of nearly 500 hectares (1,235 acres) of forest lost in 2003-2004, only 2.55 hectares (6.3 acres) were affected between February 2024 and February 2025.
“One of the greatest achievements of this work is that illegal logging in the core zone of the Monarch Butterfly Biosphere Reserve has been virtually eradicated since 2008,” María José Villanueva, WWF Mexico’s director, told reporters. “This means that the forests that represent the fundamental habitat for the monarch butterfly’s hibernation are being protected and conserved.”
