Annual population reports from the Xerces Society or U.S. Fish and Wildlife Service

U.S. Proposes Listing Monarch Butterfly as Threatened Amid 80% Population Decline

Dec 12, 2024, 09:10 PM

The U.S. Fish and Wildlife Service has proposed listing the monarch butterfly as a threatened species under the Endangered Species Act due to an estimated 80% decline in its migratory population. This proposal aims to provide more funding for habitat conservation projects and research to aid in the species' recovery. The focus would be on overwintering sites in California and Mexico, with the Pacific Grove Monarch Sanctuary potentially receiving a Critical Habitat designation. In Arizona, where monarchs can be found year-round, the listing could bolster ongoing conservation efforts, although no critical habitat is proposed for the state. The proposal follows advocacy from environmental organizations and could lead to restrictions on activities that harm monarch habitats, particularly on federal lands. The western monarch population has declined by 95% since the 1980s and faces a 99% chance of extinction by 2080. Habitat destruction, insecticides, and climate change are cited as key factors in the decline, with particular emphasis on the destruction of milkweed, the monarch caterpillar's only food source.