What it took to get the monarch listed as endangered – and how citizen scientists helped
The monarch butterfly’s addition to the International Union for Conservation of Nature’s endangered list marks a significant moment in wildlife conservation. The decision highlights the urgency of protecting this iconic species, whose eastern population has plummeted by around 90% in recent decades. While the announcement made headlines worldwide, the deeper story is about the thousands of ordinary people who became citizen scientists, gathering the crucial data that made the listing possible.
The monarch is more than just a beautiful insect. It is an indicator species, a living measure of ecosystem health. Its decline is a warning sign of a broader environmental crisis, reflecting the loss of habitat, the heavy use of pesticides, and the mounting challenges facing pollinators across the globe. The monarch plays a role in pollination, helping fertilize a variety of wild plants and crops, which in turn supports entire ecosystems. Safeguarding the butterfly’s future also benefits many other pollinators and the plants they depend on.
Beyond its ecological importance, the monarch’s migration is one of nature’s most remarkable spectacles. Every year, millions of monarchs travel thousands of kilometers from Canada and the United States to overwintering sites in central Mexico, with multiple generations completing the round trip. This journey, encoded in the species’ biology and passed down through generations, has deep cultural significance in many communities and immense scientific value for understanding animal navigation and adaptation. But climate change, habitat destruction, and pesticide use have placed this migration at risk of disappearing.
Tracking a species with a range that spans an entire continent is a monumental challenge. For the monarch, traditional research methods alone could not provide the necessary data. Scientists faced a species that numbered in the millions, moving unpredictably across thousands of kilometres. The only way to capture a clear picture of its population trends and migration patterns was to enlist the help of the public.
Citizen science projects like Monarch Watch and the Monarch Larva Monitoring Project became the backbone of this effort. Volunteers, from schoolchildren to retirees, tagged butterflies, counted eggs on milkweed plants, monitored caterpillar development, and tracked migration routes. They worked in gardens, fields, and along roadsides, collecting observations that, when combined, formed one of the most comprehensive wildlife monitoring datasets in the world.
This massive, long-term data collection effort provided the scientific backbone for conservationists to build their case to the IUCN. The patterns were clear: populations were in sharp decline, and the threats were widespread and persistent. Without the dedication of citizen scientists, these trends might have remained invisible until it was too late.
The work of citizen scientists did not stop at data collection. Many turned their knowledge into direct conservation action. Across North America, communities began creating monarch “waystations”, patches of milkweed and nectar plants designed to provide food and breeding grounds along migration routes. Schools planted butterfly gardens, farmers set aside strips of land for pollinator habitat, and individuals transformed backyards into safe havens for monarchs and other pollinators.
The listing of the monarch as endangered is both a warning and a call to action. It underscores the fragility of the species, but it also demonstrates how coordinated, grassroots efforts can influence global conservation policy. The monarch’s story is a model for how citizen science can bridge the gap between research and action, giving communities a direct role in safeguarding biodiversity.
As the world confronts accelerating biodiversity loss, the monarch butterfly stands as a reminder that solutions will require both scientific expertise and public participation. The endangered listing is not the end of the story but the start of a new chapter, one in which the future of the monarch rests in part in the hands of the people who helped bring its plight to light. By continuing to plant, protect, and observe, these citizen scientists are not only preserving a species but also defending the intricate web of life it represents.
