For ten days, the International Monarch Monitoring Blitz invites the North American population to locate milkweed plants and look for eggs, caterpillars, chrysalises and butterflies in order to help estimate the size of the monarch’s summer population. To take part, you need only transmit your monarch and milkweed plant observations via the Insectarium’s Mission Monarch program, or else use one of the community-science programs listed below. 

Crucial data for monarch protection 

Since monarch and milkweed populations cover a great deal of North America, the participation of the population is essential for deepening our knowledge of these two intimately connected species. Climate change is altering the monarch and milkweed range, whence the importance of collecting and analyzing reliable data over the long term if we’re to arrive at a better understanding of population and habitat trends. 

The roughly 4,000 observations reported last year helped collect invaluable data on monarch breeding all over North America. Observations from volunteers make it possible to identify priority conservation areas for the monarch and to guide conservation measures. Data collected during the Blitz are freely accessible and can be consulted on the website of the Trinational Monarch Knowledge Network, a data depository designed by the experts from the Insectarium that contains observations from a range of sources and that helps research teams carry out large-scale temporal and spatial analysis. 

The Blitz is the sole coordinated initiative on a North American scale that offers an overview of the summertime range of monarch and milkweed populations. That information is critical for scientists in their understanding and assessment of monarch reproductive success, as well as long-term population trends. That’s especially important right now, since the monarch’s eastern migratory population has reached the lowest level ever observed at the wintering sites in Mexico, over an area of 0.90 hectares, according to CONANP (Comisión Nacional de Áreas Naturales Protegidas, Mexico). Moreover, in December 2023, the monarch was officially designated an endangered species under Canada’s Species at Risk Act. 

Taking part in the International Monarch Monitoring Blitz is a concrete way to contribute to the conservation of this emblematic butterfly. By joining thousands of volunteers across North America, you’ll be helping collect crucial data on monarch populations and milkweed plants. That information makes it possible to target conservation efforts where they’re most needed. By documenting monarchs and their breeding habitats over ten days, you’re taking part in a unique and invaluable scientific initiative that no single research team could carry out by itself, and directly contributing to the protection of biodiversity

Community-science programs 

In Canada: 

• Mission Monarch (mission-monarch.org/en) 

• iNaturalist Canada (inaturalist.ca) 

In the U.S.: 

• Journey North (journeynorth.org) 

• Monarch Larva Monitoring Project (mlmp.org) 

• Western Monarch Milkweed Mapper (monarchmilkweedmapper.org) 

• iNaturalist (iNaturalist.org) 

In Mexico: 

• NaturaLista (naturalista.mx) 

• Correo Real (correoreal.mx) 

The International Monarch Monitoring Blitz is organized by the Trinational Monarch Conservation Partnership, which is the result of the collaboration of the following organizations: the Commission for Environmental Cooperation (CCE), the Comisión Nacional de Áreas Naturales Protegidas in Mexico, Environment and Climate Change Canada, the Insectarium | Space for Life, the Canadian Wildlife Federation, Journey North, the Monarch Joint Venture, Profauna A.C. in Mexico, the U.S. Fish and Wildlife Service and the Xerces Society for Invertebrate Conservation.