The monarch butterfly (Danaus plexippus) is an iconic butterfly, well-known around the world due to its striking physical appearance, global distribution, and long-distance migration patterns. Within the continental United States, monarchs occur in at least three populations, including the two migratory populations (western population, eastern population) with the Rocky Mountains acting as the general divider, and a non-migratory population in south Florida.
On December 12, 2024, the U.S. Fish and Wildlife Service (USFWS) proposed listing the monarch butterfly under the Endangered Species Act (ESA) as a threatened species with special rules for “take” exemptions. The proposed exemptions include the following:
- Activities that maintain, establish, enhance, or remove milkweed (plants where monarchs lay eggs and grow into caterpillars) and nectar plants. This includes removal of noxious weeds, livestock grazing, routine agricultural activities, fire management, silvicultural practices, maintenance of residential and commercial gardens, and vegetation management (mowing, ground disturbance) when conducted outside the time when monarchs are present.
- Implementation of conservation plans and programs.
- Maintenance or improvement of overwintering habitat.
- Vehicle strikes.
USFWS also proposed to designate critical habitat on the western populations’ wintering grounds in southern California, totaling approximately 4,395 acres across seven counties.
USFWS identified the major threats to the monarch as the availability, distribution, and quality of milkweed and nectar resources; insecticide exposure; and climate change.
WILL MY PROJECTS BE AFFECTED?
The monarch butterfly occurs in a wide range of habitats, including both natural (e.g., grasslands, shrublands) and urban landscapes, but requires the presence of milkweed and flowers to complete its natural life cycle. While the species is not found in forested landscapes within their migratory range, the monarch requires stands of trees to form dense clusters within the species’ overwintering range (southern California and Mexico).
It will be important to assess if any of your projects would modify monarch butterfly habitat. Although species proposed for listing are not protected by the ESA, federal agencies must confer with the USFWS if their actions would likely jeopardize the species’ continued existence or adversely modify proposed critical habitat. If the monarch butterfly is listed as threatened under the ESA, projects that impact monarch butterflies will need to consider whether a take permit is needed.
LEARN MORE AND GET INVOLVED
A public comment period is in place until March 12, 2025, for this proposed listing. All comments may be submitted either electronically through the Federal eRulemaking Portal or by mail. Two virtual public information meetings (registration required) will be held on January 14, 2025, from 6:00 p.m. to 8:00 p.m. ET and again on January 15, 2025, from 8:00 p.m. to 10:30 p.m. ET. Details on the proposed listing, comment submittal, and public meeting information are available in the Federal Register under docket number FWS-R3-ES-2024-0137.
SWCA CAN HELP
Let us help you craft and submit your comments on the proposed rule and critical habitat designation for the monarch butterfly. Project proponents may want to submit comments if the species or critical habitats may occur within their project area or may be affected by routine project activities, thus affecting project timelines and key business decisions. Our experienced team is ready to assist with evaluating the sufficiency of data supporting the decision and analyzing the areas considered but excluded as critical habitat and the rationale behind those decisions.
We can also help you review the timeline for the finalization of the listing decision as it relates to your project timelines, and understand how the listing may affect your ongoing or future activities.
egladding [at] swca [dot] com (Eleanor Gladding) | Pollinator Specialist and ESA Regulatory Compliance Strategist, Southwest Region
brittany [dot] irle [at] swca [dot] com (Brittany Irle) | Monarch Butterfly Specialist and ESA Regulatory Compliance Strategist, Texas Region
sharif [dot] durzi [at] swca [dot] com (Sharif Durzi) | Pollinator Specialist, California Region
kely [dot] wabnitz [at] swca [dot] com (Kely Wabnitz) | Pollinator Specialist and ESA Regulatory Compliance Strategist, Midwest and Northeast Regions
aglen [at] swca [dot] com (Amanda Glen) | Senior Technical Director – Biological Services, Nationwide