Mexico City, Mexico

In February 2024, I was invited as part of the Canadian delegation to Mexico to participate in the Trilateral Scientific Group Meeting on the Monarch Butterfly. As one of the most junior attendees, this was an amazing opportunity for me to learn from researchers and conservation practitioners from Canada, the USA, and Mexico. The objectives of the trilateral meeting were to bring together scientists from all three countries to share recent research, identify research priorities, and form cross-border collaborations. The monarch butterfly is beloved by people throughout North America, and this meeting reflected the dedication of scientists from academia, governments, and non-governmental organizations to conserve this iconic butterfly.

The monarch butterfly is probably the world’s most famous migratory insect. In the autumn, monarch butterflies east of the Rocky Mountains migrate south to overwinter in forests in central Mexico. There, they spend the winter roosting together in the boughs of fir trees, awaiting spring. Come spring, the butterflies migrate back northward, where they will re-occupy the eastern USA and Canada over three to five overlapping generations. Each year, WWF Mexico uses standardized procedures to estimate the number of monarch butterflies overwintering in Mexico, in hectares occupied. This year, this number was the second lowest ever recorded – 0.9 hectares. The number of monarch butterflies recorded overwintering in Mexico has declined over the last few decades due to multiple interacting drivers, including climate change and habitat destruction.

At the meeting, we saw firsthand what the future holds if the monarch population continues to decline. On the last day of the meeting, we visited the overwintering colony at Piedra Herrada. I was beyond excited. During fieldwork for my graduate thesis, I had followed the migration of the monarch butterfly from Texas through to Ontario by car, but I had never seen monarchs on the overwintering grounds in Mexico. This day trip offered me the opportunity to complete the loop and observe the entire annual migratory cycle. I hiked at the front of the group, out of breath but excited to finally see, firsthand, the images of clustered monarchs hanging from trees that I had first seen in National Geographic as a young girl. Instead, at the grove, we were met by another local guide, who nervously whispered, “No hay monarcas,” to our guide. Indeed, no monarchs remained in the trees, and more dead monarchs could be seen littering the forest floor like brilliant orange leaves than could be seen fluttering among the trees. It seems that high temperatures that day had driven the monarchs to seek another overwintering site. It was just bad luck - the monarchs will return to Piedra Herrada - but this brief visit offered a glimpse of a dismal future. A future where the local people who rely on the funds from ecotourism to conserve their forests have to turn to other industries, and the visitors who want to experience the wonders of nature leave disappointed. On a personal level, this brief visit left me more motivated than ever to do my part to help the monarch butterfly.

Although many questions regarding the monarch’s migration, ecology, and population decline remain, the participants of the trilateral meeting agree that conservation action should not be postponed. Instead, future research should modify and amend existing conservation activities. If you want to help the monarch butterfly, there are multiple ways to get involved. Multiple community scientist initiatives, such as Correo Real, Journey North, Monarch Watch, and Mission Monarch, monitor the monarch’s migration. At the individual level, the best action to take is to plant milkweed, the hostplant of the monarch butterfly, and native flowers, create pollinator gardens or ‘monarch waystations,’ reduce pesticide use, and encourage your local government and neighbors to do the same.

I am optimistic about the future of the monarch butterfly. Many smart, dedicated, and brave people from all walks of life are committed to helping the monarch. The monarch itself is a resilient species, with high genetic diversity and the ability to rebound its population size quickly, given favourable conditions. I hope that, with all hands on deck, the monarch will recover to a robust population size. Then, I can return to Mexico and see many millions of healthy monarchs overwintering peacefully in the forest.