Monarch butterfly numbers surge in Canadian Prairies after unusually wet, hot summer

Across the Canadian Prairies, citizen naturalists are documenting an unexpected boom in monarch butterflies, with reports of abundant caterpillars, chrysalises and adult flights in backyard milkweed patches. In La Broquerie, MaryAnn Lepp observed 20 caterpillars in a single day, and the Living Prairie Museum in Winnipeg reported a continuous flow of monarchs all summer. While scientists acknowledge that the region’s unusually wet and hot summer likely boosted numbers, they warn that historic habitat conversion to farmland still threatens the species, which was only designated federally endangered in December 2023.

Monitoring efforts rely on counting wintering colonies in Mexico, where populations are estimated at about 50 percent of sustainable levels. The Assiniboine Park Zoo also noted a rise in the critically endangered Poweshiek skipperling, suggesting broader benefits from the weather pattern. Researchers will attach tiny radio tags to adult monarchs this fall to track their migration to Mexico. Community volunteers remain committed to protecting the insects as part of broader ecosystem health.