Just days from an Endangered Species Act public comment deadline, monarch butterfly conservation groups are celebrating a report that the population doubled last season.

News of the doubling comes from 2024-2025 overwintering population counts released this week by the World Wildlife Fund-Telmex Telcel Foundation Alliance and the National Commission of Protected Natural Areas in Mexico. Measured by wintering area hectares (2.5 acres), numbers are up from 0.9 to 1.79 hectares, a 99% increase. However, 6 hectares is the considered sustainable population level for the iconic insects.

Conservation groups said the report offers hope and shows that public support and voluntary efforts make a difference, but they also need to increase.

Oklahoma Monarch Society Executive Director Katie Hawk, who just returned with an Oklahoma delegation visiting Central Mexico’s oyamel fir forests, said the news is cause for celebration.

“The monarchs are off to a great start rebounding from a big drop over these past several years,” she said. “We are grateful for the efforts of monarch enthusiasts statewide for creating critical habitat and reducing threats like pesticides. We will remain committed to collaborating with our partners and encourage the public to join us to ensure their populations continue to thrive.”

National Monarch Joint Venture Executive Director Wendy Caldwell said, “The news of the rise in the eastern monarch population is a positive sign, but there’s still much to be done. To secure the future of the monarch migration, we need to maintain this population at around six hectares. By creating more habitat for monarchs and other pollinators, we can strengthen their resilience and support long-term population stability.”

A remarkable feat

University of Kansas-based Monarch Watch reports that while a depressed monarch population doubling itself is a remarkable feat compared to mammalian or other species, this is the seventh time it has happened since 2000-2001, and it could have been better.

Four times, all in recovery from very low populations the previous year, the population has rebounded by a factor of 2.5 to 3.3, according to Monarch Watch Founding Director Chip Taylor. He said the recovery in 2024 brings the population back to 3- to 5-year running averages of late.

“A takeaway here is that monarchs demonstrate resilience over and over again. Weather knocks them down, but spectacular recoveries are the rule if negative conditions during one year are followed by favorable conditions for population growth,” he wrote in his blog this week.

He reported that heavy and continuous rain in the Upper Midwest during key summer reproductive times, late-season warmth, and drought during the fall migration from southern Canada to Mexico likely prevented a better recovery.

More work to be done

The news comes near the end of a  90-day comment period, March 12, after the U.S. Fish and Wildlife Service announced a proposal to list the monarch as threatened under the Endangered Species Act, including a 4(d) rule.

The added 4(d) rule identifies a need to increase availability of milkweed and nectar plants, enhance overwintering habitat, reduce negative impacts of pesticides, incentivize voluntary efforts, and maintain public awareness and support.

With the spring migration lifting off in Mexico, the Oklahoma Monarch Society and other groups in the state are planning numerous educational events and plant sales across the state in the coming weeks, Hawk said. For example, the Society and OG&E are hosting a “Pollinator Party in the Park” in Woodward on May 31st. Attendees can shop multiple native plant and seed vendors, make seed bombs, and participate in a variety of activities, Hawk said.

She said the Society, representing a consortium of dozens of public and private Oklahoma organizations, provides a wide range of advice about helping monarch butterflies, including what to plant, how to build, and where to buy native plants for pollinators. The nonprofit is funded through public donations and revenue from the “Save the Monarchs” license plate.

People can learn more at the Society’s educational website, okiesformonarchs.org.