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This fact brief was originally published as an experiment to test the concepts behind fact briefs.

Readers should be aware that while there is still a lot of useful information in fact briefs like this one, not all of them reflect Gigafact's current methods and standards for fact briefs. If you come across any that you feel are out of date, don't hesitate to contact us at support@gigafact.org.

FACT BRIEF

Did the most recent annual count suggest that 99% of Western monarch butterflies have been wiped out?

Tuesday, June 8, 2021

By Jacob Alabab-Moser

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YES

Annual counts of Western monarch butterflies in California and northern Baja California by volunteers during Thanksgiving 2020 and New Year's 2021 found that a population decline has accelerated in recent years. The Thanksgiving count—1,914 monarchs—reflected a 99.9% decrease from the 1980s. Counts at specific sites where thousands of monarchs spent the winters past in found only a few hundred, or, in the case of some sites like Pacific Grove, California, none.

The Xerces Society for Invertebrate Conservation, a nonprofit that coordinates the counts, cites habitat loss and degradation, warming and other climate changes, pesticides, and loss of milkweed and other flowering plants as compounding factors in the Western monarch's endangerment.

The U.S. Fish and Wildlife Service and a California state court recently denied monarchs protection under national and state endangered species laws.

This fact brief is responsive to conversations such as this one.

Sources

Xerces Society for Invertebrate Conservation Western monarch population closer to extinction as the wait continues for monarchs’ protection under the Endangered Species Act

Xerces Society for Invertebrate Conservation Fifth annual Western monarch New Year’s count confirms continued decline in Western monarch population

KAZU (Monterey, CA) A winter without monarchs In Pacific Grove—Butterfly Town, USA

US Fish & Wildlife Service Assessing the status of the monarch butterfly

Superior Court of California, Sacramento County Ruling on insects’ eligibility under the the California Endangered Species Act

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Gigafact

Between 2020 and 2022, under close editorial supervision, Gigafact contracted a group of freelance writers and editors to test the concepts for fact briefs and provide inputs to our software development process. We call this effort Gigafact Foundry. Over the course of these two years, Gigafact Foundry writers published over 1500 fact briefs in response to claims they found online. Their important work forms the basis of Gigafact formats and editorial guidelines, and is available to the public on Gigafact.org. Readers should be aware that while there is still a lot of relevant information to be found, not all fact briefs produced by Gigafact Foundry reflect Gigafact's current methods and standards for fact briefs. If you come across any that you feel are out of date and need to be looked at with fresh eyes, don't hesitate to contact us at support@gigafact.org.

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About fact briefs published on Gigafact

Fact briefs are short, credibly sourced summaries that offer “yes/no” answers in response to claims found online. They rely on publicly available, often primary source data and documents. Fact briefs are created by contributors to Gigafact —a nonprofit project looking to expand participation in fact-checking and protect the democratic process. See all fact briefs here.