Beneficial insects

Help Conserve Monarch Butterflies by Being Part of a Monitoring Network across North America

A composite of five different views of a monarch emerging from its chrysalis. Photo: Commission for Environmental Cooperation

Follow the Blitz on social media at #MonarchBlitz

Join hundreds of volunteers in Canada, Mexico and the United States, from July 27 to August 4, for the 2019 International Monarch Monitoring Blitz (the Blitz) and be part of this regional initiative to help conserve the monarch butterfly (Danaus plexippus). By participating, you can help monarch experts gain more information to understand the distribution of the migratory monarch butterfly in North America.

“Observations from the public can help scientists gain valuable information that will support regional efforts to protect the monarch butterfly and its habitat all along its migratory flyways,” said André-Philippe Drapeau Picard, Mission Monarch coordinator at the Insectarium/Montréal Space for Life.

For one week, the Blitz invites people across North America to go out to gardens, parks and green areas and monitor milkweed plants for monarch eggs, caterpillars, chrysalises and butterflies. This information will help researchers identify priority areas for monarch conservation actions. Data gathered during the Blitz will be uploaded to the Trinational Monarch Knowledge Network, where they will be accessible for anyone to consult and download.

To take part in the Blitz, go to Mission Monarch page if you are in Canada. If you are east of the Rocky Mountains in the United States, follow the Monarch Larva Monitoring Project link, and if you are west of the Rocky Mountains, use the link for the Western Monarch and Milkweed Mapper. In Mexico, you can go to Naturalista. Or, simply follow the Blitz on social media, using the hashtag #MonarchBlitz.

Monarch butterfly overwintering sites were first recorded by scientists in California over 200 years ago and in Mexico in 1975. Since then, the monarch has become an emblematic species for North America. After an alarming decrease in its populations over the last 20 years, the eastern monarch population overwintering in central Mexico showed a significant increase this past winter. However, the population is still well below historic levels, which inspires questions about what conservation efforts are needed to continue this positive trend.

Meanwhile, the western monarch overwintering population along coastal California hit an all-time low this winter, with less than 1% of the historic population size remaining. Public participation in community science in the West is more important than ever to help understand and reverse this population’s dramatic decline.

“The majestic monarch butterfly, a flagship North American pollinator and symbol of international cooperation, needs your help with its spectacular annual migration across the continent. Join us by contributing to the International Monarch Monitoring Blitz,” says Cora Lund Preston, Communications Specialist at the Monarch Joint Venture.

The Blitz is an initiative of the Trinational Monarch Conservation Science Partnership, created through the Commission for Environmental Cooperation (CEC). Through the Blitz, scientists from the Insectarium/Montréal Space for LifeEnvironment and Climate Change Canada (ECCC), Monarch Joint VentureJourney North, the US Fish and Wildlife Service, the Xerces Society for Invertebrate Conservation, and Mexico’s Comisión Nacional de Áreas Naturales Protegidas (Conanp) are asking the public to help them understand monarch and milkweed distribution throughout North America.

Media Contact – CEC
Sarah Julien
514 781 2781
Monarch Project Lead – CEC
Georgina O’Farrill
Blitz Coordinator – Insectarium/Montréal Space for Life
André-Philippe Drapeau Picard


  • Community science, also called citizen science and participatory science, is the process by which non-scientists contribute actively and voluntarily to research projects.
  • 486 participants across Canada, Mexico, and the United States
  • 1,323 observations
  • 53,588 milkweed plants monitored
  • 13,796 monarchs observed
  • 6,905 eggs
  • 4,900 caterpillars
  • 470 chrysalises
  • 1,521 butterflies


  • Monarch butterflies weigh less than a gram.
  • There are two recognized migratory routes in North America: Eastern and Western.
  • Migration covers 3,000-5,000 km (2,000 to 3,000 miles) that span over three countries.
  • The Eastern migratory population has declined by more than 80% in 20 years, while the Western population has declined by more than 90%.
  • Everyone can help the monarch by participating in community science, creating habitat and spreading the word.

Texte adapted from a press release by the Commission for Environmental Cooperation

Garden writer and blogger, author of 65 gardening books, lecturer and communicator, the Laidback Gardener, Larry Hodgson, passed away in October 2022. Known for his great generosity, his thoroughness and his sense of humor, he reached several generations of amateur and professional gardeners over his 40-year career. Thanks to his son, Mathieu Hodgson, and a team of contributors, will continue its mission of demystifying gardening and making it more accessible to all.

3 comments on “Help Conserve Monarch Butterflies by Being Part of a Monitoring Network across North America

  1. This is one of the most sensible article about butterflies lately!
    I happened to live near Monarch Grove when I was in school in the late 1980s. Tourists came to town while the monarch butterflies swarmed the blue gums and red gums (eucalypti) just to the south. It was spectacular. The problem I had with it is that no one mentioned how this swarming might affect the surrounding ecosystem. We really had no idea if the butterflies who swarmed the blue and red gums were neglecting the native species that relied on them for pollination. Now that butterfly gardening and pollinator gardening is a fad, we really should know more about how butterflies behave, and if the natural ecosystem will miss those who are so happy to come to our gardens.

  2. I recently learned my neighbor has a registered Monarch butterfly Waystation. I hope I get some traffic as a byproduct.

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