Photo by Joshua J. Cotten, Unsplash.

November 1, 2022

Conservation Status of the Monarch Butterfly

Four black, white, and yellow striped caterpillars of different sizes are on a green leaf. To the left of the caterpillars on top of the green leaf is a green cocoon and a tiny green insect egg.
Different stages in the monarch lifecycle. Photo by Brett Billings, USFWS.

Earlier this summer the monarch butterfly was in the news as the International Union for Conservation of Nature (IUCN) designated the migratory species as “endangered” on its Red List of Threatened Species. This announcement sparked some misunderstanding as many confused the IUCN Red List with the U.S. Federal Endangered Species List. Both systems include a designation of “endangered,” but each means something different for the monarch. And for all of us.

IUCN vs USFWS Endangered Status

IUCN is an international organization and one of the world’s leading authorities on the extinction risk of the many thousands of species it has assessed globally. While endangered status on the IUCN Red List is of grave concern, it does not have the regulatory implications that endangered status carries if the monarch were listed as endangered on the U.S. Federal Endangered Species list.

The U.S. Fish and Wildlife Service (USFWS) is responsible for assessing each species’ “endangered” status here in the U.S. When a species is listed, the Endangered Species Act (ESA) mandates its protection in the U.S., which carries legal and regulatory weight. It requires all of us to take action to protect a struggling species, which can impact everything from industry to home gardeners.

What Happens if Monarch’s are Listed in the U.S.?

Tan, dried seed pods hang from a milkweed plant stalk on the edge of a corn field awaiting harvest. The seed pods are open exposing fluffy white fibers attached to small dark brown seeds which are about to float off in the wind.
Photo by Patty Gillespie.

If monarchs become protected under the ESA, it stands to reason that their habitat would fall under protection, too. The critical part of monarch habitat is not a single mountain range or even the confines of a single state. It is tied to a widely distributed (though increasingly diffuse) set of plant species—the milkweeds. These plants are their sole source of food as caterpillars and an irreplaceable part of the caterpillar’s life cycle.

There are many as-yet unanswered questions about a potential listing of the monarch under the ESA. Would pulling a random milkweed that pops in your garden be rendered illegal? Weed control in agriculture has long been tied to milkweed declines; what regulatory implications would a monarch listing have on farmers? Similarly, activities such as monarch rearing or monarch tagging would have implications, likely requiring permits to perform these endeavors.

The USFWS has carefully considered the monarch’s conservation status and, after delaying the decision for some time, finally decided in 2020 not to designate the species as endangered. The USFWS will reassess the status in 2024, but for the time being, our actions related to both monarchs and milkweeds are not impacted.

What Does This Mean for Illinois?

The Illinois Endangered Species Protection Board (IESPB) reviews and revises the endangered and threatened species list based on the conservation status of the species only within Illinois. The Federal ESA evaluations are accomplished using the full distribution of the species. There is, however, a provision within the Illinois Endangered Species Protection Act that automatically places federally designated threatened or endangered species on the Illinois list.

To learn more about the Illinois process for designating endangered or threatened species visit these sites:

Duties and Responsibilities – Endangered Species Protection Board (

The Illinois List Review and Revision – Endangered Species Protection Board

What do IUCN or USFWS Decisions Mean for Us?

A black, orange, and white monarch butterfly rests on the topmost oval leaf of a green milkweed plant. The milkweed plant is surrounded by tall grasses and green vegetation.
Photo by Ryan Hagerty, USFWS.

Many of us held our breath as USFWS assessed this decision in the years leading up to 2020. For anyone who deals with areas where milkweeds grow, endangered designation can affect a variety of activities.

For biologists like myself, it is important to hear the USFWS assessment and conclusion since it takes into account all the recent science, plus a wide range of monitoring data across our continent. It represents a comprehensive review of the available information to determine how we can prevent a species from going extinct. The designation of endangered is a major sign that the species is in trouble and drastic measures must be taken to ensure it doesn’t disappear.

The same can be said for the IUCN designation as it represents a comprehensive review from an authority on biodiversity. This designation serves as a message to the global community that actions must be undertaken, but it does not require action in the U.S. under the ESA. While some groups have brushed the IUCN designation off as less meaningful, it should serve to reinforce the importance of efforts that so many of us are taking to protect Illinois’ state insect.

Monarch Conservation Efforts are Increasing

A black, yellow, and white striped caterpillar has almost completely devoured a green leaf. Just a little of the leaf remains.
Photo by Josie Weiss, Unsplash.

On the bright side of things, the conversation around monarch decline has brought a ton of awareness and subsequent actions to conserve habitat. Many rights-of-way owners, such as rail companies and power plants, have entered into agreements that preemptively protect monarch habitat in exchange for looser regulations should the monarch be listed.

In the agricultural community, it has prompted some producers to add pollinator habitat to their production areas, allowing space for milkweeds to flourish in agricultural landscapes. Incentive programs put in place by the Farm Bill have really driven this addition of habitat across the monarch’s range in the U.S.

As gardeners, we all are aware of milkweeds these days. Many of us are actively planting milkweeds and anxiously watching for signs of monarch caterpillars. We know that a diversity of floral resources during fall migration is incredibly important and many of us are designing gardens to maximize floral resources.

Researchers have responded with a growing body of work looking at all aspects of the monarch lifecycle to find ways we can solve this problem and perpetuate the species. Every year we are gaining more and more valuable information to help assess the conservation status of this species.

I hope that someday the story of the monarch butterfly is a conservation success, similar to that of the bald eagle. In the meantime, we all need to stay engaged in monarch conservation activities to ensure this charismatic species endures.

Ryan Pankau has more than two decades of experience as a forester and arborist, building his lifelong love of trees into the career he enjoys today. Beyond trees, he has also focused on integrating the concepts of ecology into the management of plants in the built environment to create more resilient landscapes that better support the native flora and fauna of Illinois. He is currently a Horticulture Educator for University of Illinois Extension serving Champaign, Ford, Iroquois and Vermilion counties.

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