One of the most special moments of spring is watching the beautiful Monarch Butterflies return to southern Canada.
This year, we also have positive news to share about the eastern Monarch population!
Eastern Monarch Butteflies leave their winter refuge (the Oyamel Fir forests of central Mexico) around the end of March. Following blooming milkweed plants, these incredible travellers breed and lay eggs as they migrate north. The butterflies who overwintered in Mexico produce their first generation of offspring in the southern U.S. Then the new generation continues to journey up through eastern breeding grounds during the months of April and May.
Monarchs rely on nectar-rich flowers to fuel their journey, and they should start arriving in Canada the week of early June, 2025! The butterflies are a bit later this year, as they’re often seen in southern Ontario closer to the beginning of May.
Current reports show that adult Monarchs have been sighted in Flat Rock, Michigan – just across the Detroit River from Amherstburg, Ontario.
We can roughly expect to see Monarch Butterflies arriving south of the Greater Toronto Area in the next few weeks. From there we’ll see them arrive north of GTA, as well as in Manitoba, Quebec, and then the Maritimes. Depending on weather conditions and the abundance of blooms, Atlantic Canadians should see Monarchs arrive in the first weeks of June.
Good News!
The Monarch winter 2024-2025 population numbers were released in March. The butterflies appeared to occupy 1.79 hectares of forest compared to 0.9 hectares last year, which is a hopeful sign for an Endangered Species. We were thankful for this positive news. At the same time, we need to remember that the Monarch Butterfly population is still below the average of the last decade, and that the population remains low and vulnerable.
Collaboration between Canada, the US and Mexico is vital as we develop an action plan for their recovery.
Canada contributes 17% of the overwintering population, so we have a role to play in its recovery. Everyone can help.” ~Carolyn Callaghan, CWF Senior Conservation Biologist, Terrestrial Wildlife.
Through scientific research, education and on-the-ground conservation work, the Canadian Wildlife Federation is carrying out major initiatives for the Monarch Butterfly.
How We’re Helping the Monarch Butterfly
Creating Pathways
The Rights-of-Way team continues to facilitate the creation of native meadow habitat for Monarch Butterflies by supporting and empowering land managers in Ontario and Quebec as crucial partners in the conservation effort. In the GTHA, CWF is working with 12 partnering organizations to restore Monarch and pollinator habitat across 17 projects! Learn more about the 1,795 hectares of high-quality pollinator habitat CWF and its partners have restored in Ontario.
The Kaleidoscope Project
The Kaleidoscopes are members of the iNaturalist community that help track Monarch Butterflies by making observations and uploading them to the Monarch Migration in Ontario Group on iNaturalist Canada. With your help, you can contribute to biodiversity science in your community. Join today for free and share your findings on Monarch Butterflies!
Learn more about our work with pollinators >
Brie Laird
Brie is the Communications and Marketing Manager at the Canadian Wildlife Federation. She works alongside the science and education teams to help develop and implement marketing and communications strategies. In her spare time, she enjoys uploading observations to iNaturalist to learn more about the vast amount of species in Canada.
