Historically, western monarchs have made a spectacular annual migration to overwinter in forested groves along the coast of California. Each spring, the butterflies fan out across the West to lay their eggs on milkweed and drink nectar from flowers in Arizona, California, Nevada, Oregon, Washington, Idaho, and Utah.
However, the western migration is in trouble. In recent years, the number of monarchs making the annual journey to coastal California has declined by >90%. In response to this, the Xerces Society has spearheaded the Western Monarch Call to Action, working in partnership with universities, government agencies, other organizations, and communities to stabilize and recover this imperiled population.
These actions are building upon the Xerces Society's decades of western monarch conservation work. Western populations have been less well-studied than their eastern counterparts, and have unique conservation needs. To that end, the Xerces Society conducts annual surveys of overwintering populations; assesses the status of overwintering sites; provides guidance for the management of breeding, migratory, and overwintering habitat; advises on habitat establishment and restoration; and researches the distribution of monarchs and milkweed in the West.
A set of rapid-response conservation actions that, if applied immediately, can help the western monarch population bounce back from its extremely low overwintering size. The goal of this call to action is to identify actions that can be implemented in the short-term, to avoid a total collapse of the western monarch migration and set the stage for longer-term efforts to have time to start making a difference.