The U.S. Fish and Wildlife Service is announcing a proposal to list the monarch butterfly as a threatened species with species specific protections and flexibilities to encourage conservation under section 4(d) of the Endangered Species Act. The prohibitions and exceptions in the proposed rule affect monarch butterflies only in the contiguous United States, Puerto Rico and U.S. Virgin Islands (the monarch’s historic range). 

Our agency is also announcing 4,395 acres (1,778 hectares) of proposed critical habitat in the species’ overwintering habitat in Alameda, Marin, Monterey, San Luis Obispo, Santa Barbara, Santa Cruz and Ventura counties, along coastal California.

The proposal, which appears in the Federal Register on December 12, 2024, opens a 90-day public comment period that ends on March 12, 2025. The proposed rule and supporting documents are available online at regulations.gov under docket number FWS-R3-ES-2024-0137.

With its iconic orange and black markings, the monarch butterfly is one of North America’s most recognizable butterfly species. Monarchs are known for their impressive long-distance migration and large clusters they form while overwintering. Their bright coloration serves as a warning to predators that eating them can be toxic. 

Originally native to North America, the monarch butterfly has dispersed to other parts of the world and is now non-migratory and found from the islands in the Pacific Ocean to the western edge of Europe. Despite the expansion, most monarchs continue to live and migrate in North America. North American monarchs are divided into eastern and western migratory populations. In both the eastern and western North American populations, the spring monarch migration represents a massive annual range expansion as they leave their breeding grounds and disperse across the country. The Rocky Mountains divide these two populations, limiting their contact.However, the two populations are not completely isolated from each other and still occasionally interbreed. There are also non-migratory monarchs that remain year-round at the southern end of their breeding range in North America, including in parts of Florida, the Gulf Coast, the southern Atlantic Coast and the southern Pacific Coast.

Eastern North American Monarch: The larger population of monarchs, in both individuals and range, is the eastern North American migratory population. These monarchs are found in 70 percent or more of the North American monarch range. In the fall, they may fly over 2,000 miles (3,000 km) to reach overwintering sites in Mexico. After overwintering, the monarchs fly northward into the southern U.S. in search of milkweed, their host plant, to begin laying eggs. 

Western North American Monarch: The western North American migratory monarchs are found west of the Rocky Mountains. These monarchs live in warmer climates and generally migrate every fall 300 to 1,000 miles (about 500 to 1600 km), a much shorter distance than the eastern population. The western North American migratory monarchs overwinter in hundreds of groves (clusters of trees) along the California coast and into northern Baja California, Mexico. In the spring, these monarchs disperse from overwintering grounds traveling through California and the Western U.S. in search of milkweed to lay eggs and begin the breeding season.

Monarch butterfly populations are in peril. Based on scientific information, summarized in our species status assessment, migratory monarchs in North America are declining and are projected to continue declining over the next 60 years. Our assessment is based on evaluating the following threats:the ongoing impacts from loss and degradation of breeding, migratory, and overwintering habitat; exposure to insecticides; and effects of climate change climate change
Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.

Learn more about climate change . Probability of extinction for the eastern migratory North American population ranges from 56 to 74% by 2080. And in the west, by 2080, probability of extinction is greater than 99%. We determined that the species meets the definition of threatened under the Endangered Species Act, meaning it is likely to become endangered within all or a significant portion of its range in the foreseeable future.

Our agency uses a Species Status Assessment to evaluate species and determine whether it needs protections. Learn more about the SSA on our Questions and Answers: Monarch SSA webpage.

If the proposal to list monarchs as threatened under the Endangered Species Act (ESA) with a 4(d) rule is finalized, it will grant monarch butterflies federal protection. Under the ESA, our agency has broad authority to determine what protections are necessary and advisable to further the conservation of threatened species. It allows us to tailor protections to prevent the further decline of the species and to help facilitate recovery. The 4(d) rule is intended to incentivize proactive conservation efforts and encourage the public to engage in monarch conservation. Our goal is to substantially increase breeding and migratory habitat through voluntary efforts.

Monarchs in the historical range of the species

Our proposed rule would list monarchs wherever found and provide protections to monarchs in their historical range. The proposed 4(d) rule prohibitions apply to monarch butterflies in the contiguous United States, Puerto Rico and U.S. Virgin Islands. Our proposed 4(d) rule is intended to incentivize proactive conservation efforts and allows actions that benefit monarchs or that have minimal impacts to monarchs and that do not threaten the species.

Monarchs outside the historical range

The proposed prohibitions would apply throughout the species’ historical range, on both public and private lands in the contiguous United States, Puerto Rico, and U.S. Virgin Islands. We are not proposing to prohibit these activities in Hawaii or other U.S. Territories because these areas are outside the historical range of the species and monarchs in these areas do not contribute to recovery of the species in North America. We are also not proposing to prohibit these activities in Alaska because the species does not occur there.

While the proposed prohibitions would not apply to activities in Hawaii or other U.S. Territories, Section 7 Section 7
Section 7 Consultation The Endangered Species Act (ESA) directs all Federal agencies to work to conserve endangered and threatened species and to use their authorities to further the purposes of the Act. Section 7 of the Act, called "Interagency Cooperation," is the mechanism by which Federal agencies ensure the actions they take, including those they fund or authorize, do not jeopardize the existence of any listed species.

Learn more about Section 7 (a)(2) of the Endangered Species Act still applies. Section 7 requires federal agencies to ensure that the activities they authorize, fund, or carry out are not likely to jeopardize the continued existence of any listed species or destroy or adversely modify its critical habitat.

Yes. Activities that may maintain, enhance, remove or establish milkweed and nectar plants within the breeding and migratory range are allowed under the proposed 4(d) rule for monarch butterflies so long as these activities do not result in conversion of native or naturalized grassland, shrubland or forested habitat. Our goal is to substantially increase breeding and migratory habitat through voluntary efforts by encouraging land management and gardening practices that have a net benefit for monarchs. We expect localized removal of milkweed and nectar plants will be outweighed by an overall addition of these resources across the landscape, making broadscale public support for monarch conservation vitally important. Given the need to restore large swaths of land with milkweed and nectar sources for the monarch butterfly, we encourage everyone to take part in voluntary conservation measures and habitat restoration efforts for monarchs. Learn more at Questions and Answers: Monarch butterfly proposed 4(d) rule webpage.

Yes, although states may have their own regulations. Collecting, captively rearing and releasing monarchs has inspirational and educational value and can foster lifelong connections to nature. Captive rearing is defined as holding of caterpillars, pupae or adults and raising them in captivity long enough for them to move to the next life stage or reproduce. 

The overall impact of collecting, possessing, captively rearing and releasing fewer than 250 individual monarchs at one location or facility is not expected to negatively affect conservation and recovery efforts for the monarch butterfly. We consider homes, botanical gardens, schools and businesses as one location or facility.

The exceptions in this proposed 4(d) rule do not apply to clustering monarchs. Do not collect or handle overwintering and clustering monarchs as this can spread disease and can impact the population and species ability to migrate or to survive the winter.

If handling greater than 250 monarchs in a given year, you will need to apply for a permit from the U.S. Fish and Wildlife Service.

In some cases, state natural resource agencies and local governments have their own monarch butterfly rules and regulations. This can include prohibitions on importation and/or interstate movement, captively rearing, and releasing monarch butterflies. You may need a state permit for scientific collection or educational activities. Please check with your state-specific and local agencies for more information.

A permit from USDA-Animal and Plant Health Inspection Service (APHIS) is required for the importation, interstate movement, and environmental release of butterflies, including monarchs. In addition, APHIS does not allow the movement of monarchs across the Continental Divide for environmental release.

Learn more on our Questions and Answers: Monarch butterfly proposed 4(d) rule webpage.

Monarch butterflies may be struck by vehicles and killed during normal driving activities. Based on analysis of the best available science, we found that vehicle mortality does not have significant impact on the monarch butterfly population as a whole. Therefore, hitting a monarch with your vehicle is not considered a violation of the ESA. Learn more on our Questions and Answers: Monarch butterfly proposed 4(d) rule webpage.

Despite losses due to collisions, research suggests that strategic improvements to roadside monarch habitat can yield a net benefit to the species. Habitat along roadsides may provide milkweed and nectar plants in otherwise heavily developed and agricultural regions. These much-needed pollinator oases can increase habitat connectivity across the landscape.

The proposed rule and supporting documents are available online for review in the Federal Register under docket number FWS-R3-ES-2024-0137. Any final actions resulting from this proposed rule will be based on the best scientific and commercial data available. To allow verification of any scientific or commercial information included in comments, please include sufficient information with your submission such as scientific journal articles or other publications.

(1) Electronically: Go to the Federal eRulemaking Portal: regulations.gov. In the Search box, enter FWS-R3-ES-2024-0137 which is the docket number for this rulemaking. Comments must be received by March 12, 2025.

(2) By hard copy: Submit by U.S. mail to: Public Comments Processing, Attn: FWS-R3-ES-2024-0137, U.S. Fish and Wildlife Service, MS: PRB/3W, 5275 Leesburg Pike, Falls Church, VA 22041–3803.

(3) During a public hearing: Virtual public hearings will be held on January 14, 2025 from 6:00 p.m. to 8:30 p.m. EST and January 15, 2025 from 8:00 p.m. to 10:30 p.m. EST.

We are seeking comments about species biology, taxonomy, range, population trends, threats, species status, including:

• Any new scientific or commercial information about alternative migratory pathways
• Population dynamics and contributions from the nonmigratory populations, specifically resident monarchs in southern Florida, the Gulf Coast, the southern Atlantic Coast, and the southern Pacific Coast

We are seeking comments about the proposed 4(d) rule to assist us in applying or issuing protective regulations under section 4(d) of the Endangered Species Act, including:

• Whether the provisions related to the maintenance, enhancement, removal, or establishment of milkweed should be revised to include spatial or temporal restrictions or deferments;
• Whether we should include an exception for the use of pesticides and, if so, what measures are reasonable, feasible, and adequate to reduce or offset pesticide exposure to monarchs, including measures for specific classes of pesticides, pesticide uses, and application methods;
• Whether we should include an exception for direct impacts from transportation and energy infrastructure, including mortality from collisions with wind turbines; and
• Whether we could improve or modify our approach to the 4(d) rule in any way to provide for greater public participation and understanding, or to better accommodate public concerns and comments.

We are seeking comments about the proposed critical habitat, including any additional areas in the United States, especially in breeding, migratory, or overwintering areas.

For full information about the types of public comment we are requesting, see our proposed rule. Please include sufficient information with your submission (such as scientific journal articles or other publications) to allow us to verify any scientific or commercial information you include.

Through March 12, 2025, we are gathering public comments and encouraging the submission of any new information. Over the rest of the year, we will review these comments and write the final decision. The final determination may differ from the proposal because our agency will consider all comments received during the comment period as well as any information that may become available after the proposal. Protections for the monarch butterfly would apply after the effective date of a final rule.

You can plant native milkweed and nectar plants. 

One of the main reasons that monarchs declined is because of the historical loss of habitat. We define monarch habitat as areas with milkweed and nectar plants. To bring back habitat on the landscape, everyone can help conserve monarch butterflies by planting native milkweed and nectar plants throughout the monarch's range. Monarchs solely depend on milkweed during the egg and caterpillar stage, and adult monarchs frequent flowers for their nectar. Adult monarch butterflies require a diversity of flowers spring through fall to ensure they have food in both their migratory and breeding habitat. 

Pollinator gardens that contain native milkweeds and flowers can help many pollinators, including monarchs. There are several examples of how people are already making a positive impact for monarchs and other pollinators by growing native pollinator gardens. You can also learn how to start your own pollinator garden and be sure to remember night pollinators!

The U.S. Fish and Wildlife Service’s Partners for Fish and Wildlife Program,Coastal Program, and USDA’s Natural Resources Conservation Service provide technical and/or financial assistance to landowners who would like to create pollinator habitat on their land. 

Our agency also works with energy and transportation sectors through the Rights of Way as Habitat Working Group and Candidate Conservation Agreement with Assurances for the Monarch Butterfly.

It is important to plant native milkweed plants for monarchs, as non-native milkweed plants can harm monarchs, even if well intended. Non-native milkweed plants, like tropical milkweed (Asclepias curassavica) in some areas of the country, can lead to increased spread of a monarch parasite, Ophryocystis elektroscirrha (OE), leading to reduced monarch survival. If you have non-native milkweeds, please cut them back in the fall to mimic native plants and discourage monarchs from breeding during the overwintering period to help reduce spread of OE. Through planting native milkweed and nectar plants, we can help ensure plentiful resources to conserve pollinators, including monarchs.

No. Captive rearing can pose risks to wild monarch populations, such as through the spread of diseases and loss of genetic diversity. There are also potential negative effects to the fitness of individuals and their migratory capabilities. The negative effects can greatly impact wild monarch populations when captive rearing is conducted on a large scale.

Collecting, captively rearing and releasing monarchs has inspirational and educational value and can foster lifelong connections to nature. The proposed rule defines captive rearing as holding of caterpillars, pupae or adults and raising them in captivity long enough for them to move to the next life stage or to reproduce. If protocols are followed to minimize disease and genetic impacts, small-scale captive rearing can reduce the risk of negatively affecting the larger monarch population while maintaining inspirational and educational benefits. For the purposes of this proposed rule, we describe small-scale captive rearing as collection, raising, and releasing 250 or fewer monarchs in a given year. If our proposed rule is finalized, we would consider the collection, raising, and releasing of more than 250 monarchs per year to be a large-scale endeavor, for which a permit would be required through Section 10(a)(1)(A) of the Act. 

Collection of monarchs at any life stage from the wild has the potential to pose a risk to population numbers; however, we evaluated the threat of collection and determined there is no evidence the current rate of collection, in combination with the current rate of release, is affecting monarch populations.

The exceptions in this proposed 4(d) rule do not apply to clustering monarchs. Do not collect or handle overwintering and clustering monarchs as this can spread disease and can impact the population and species ability to migrate or to survive the winter.

To improve future conditions so that the monarch migratory populations stabilize and grow, we need to (1) achieve a significant increase in the availability of milkweed and nectar plants in monarch breeding and migratory areas; (2) protect and enhance overwintering habitat; (3) avoid and minimize impacts to monarchs and their habitat from insecticides and herbicides; and (4) maintain public support for the conservation of monarch butterflies. 

Everyone can play a role in saving the monarch butterfly 

Unlike with some imperiled species, the monarch’s general habitat usage and wide distribution mean all people and sectors across the United States can take action to conserve monarch butterflies. Monarch conservation can occur on land ranging in size from quite small to very large, including gardens, parks, grasslands, agricultural areas and more. Monarch conservation needs an approach that encourages and incentivizes landowners to add milkweeds and nectar plants and implement actions to maintain pollinator habitat.

Conserving eastern monarchs

Conservation efforts for the eastern North American monarchs focuses on increasing overwintering monarch populations with a goal of adding more than a billion stems of milkweed on the landscape by 2038, as outlined in the Mid-American Monarch Conservation Strategy. Twenty-nine states have agreed to participate in the strategy, which will also need support from private landowners, agricultural and non-governmental organizations, state and local governments.

Conserving western monarchs

To support western North American monarch butterflies, conservation efforts focus on improving the habitat of overwintering sites in California by working with landowners on site-specific plans and increasing milkweed and nectar plants across the western breeding and migratory range, including availability of early breeding season milkweed. Six states are part of the Western Monarch Butterfly Conservation Plan (Arizona, California, Idaho, Nevada, Oregon, Utah and Washington) and comprise the core of the western monarch range.

Working with Canada and Mexico

Monarch butterflies do not recognize boundaries, flying as far north as Canada in the summer and wintering in Mexico. The effort to conserve monarchs is an outstanding example of international conservation collaboration. The three nations pledge to work together to protect monarchs and to take collective action to reverse its decline and return this incredible species to health across North America.