Monarch Butterflies Are on the Move — Here’s How to Help Them on Their Way

Among autumn’s falling leaves, you might see a familiar flash of black and orange against the blue sky. Once again, migratory monarch butterflies are on the move from their summer breeding grounds to their overwintering habitats. These spectacular insects travel up to 2,500 miles across the Americas, sometimes covering 50-100 miles a day. Like migrating birds, monarchs are the only butterfly that’s known to make a two-way migration — and they must, because neither adult monarchs or their larvae can survive the cold winter temperatures of northern climates. 

How to Spot Monarchs 

First of all, not all monarchs are migratory. When talking about threatened species of monarchs, we’re referring to specific types of monarchs within the species Danaus plexippus that make these long cross-country journeys. Migrating monarchs are broken down further into either eastern or western monarchs, based on which side of the Rocky Mountains they’re found. Eastern monarchs spend the winter in Mexico’s Sierra Madre Mountains, and the western monarchs in California. 

While migrating monarchs travel through much of North America, according to the U.S. Fish and Wildlife Service, there are several hotspots where monarch enthusiasts often gather during fall migration season. The butterflies pass through St. Mark’s National Wildlife Refuge in Florida as early as August, and a little later in September or early October, they visit the eastern shore of Virginia National Wildlife Refuge in Virginia. The Neal Smith National Wildlife Refuge is also known for its large numbers of monarchs during migration, which benefit from the refuge’s native plants and restored prairie tallgrass.

Migration varies, however. Residents of Spokane, Washington were surprised to see far more migratory monarchs than usual this year. Of course, if you live in Mexico or California, you have the privilege of seeing the monarchs in their overwintering grounds for a much longer spell. Pismo Beach in San Luis Obispo, Natural Bridges State Beach in Santa Cruz, and the Pacific Grove Monarch Butterfly Sanctuary in Monterey are among the best locations to see the overwintering monarchs in the United States.

Unlike some migrating birds, monarchs only fly during the day. They come down to roost at night, usually gathering close together in sites that are used year after year. Pine, fir, and cedar trees are popular rooting spots for their thick canopies that keep temperature and humidity controlled. In the morning, the butterflies come out into the sun to warm up before heading out again. If you live near a peninsula, that’s the perfect place to go monarch-watching. These landforms have a funneling effect, and monarchs will congregate at their tips while trying to find the shortest distance over open water, and waiting for winds that might help them along. 

When the butterflies go back north in the summer, check out Journey North, which tracks their northern migration. Monarch Joint Venture also has resources for tracking monarchs as they move through North America, wherever you’re located. 

How Are Monarchs Threatened? 

These beautiful insects, however, are threatened with extinction. Widespread use of pesticides, habitat loss, and climate change are all major contributing factors in their decline. Between the 1980s and 2021, western monarchs declined by about 99.9%, from about 10 million to fewer than 2,000. Between 1996 and 2014, the eastern population (which is larger) dropped by 84%. Last year their populations declined sharply, and monarch presence in wintering grounds dropped 22%, and their habitat from 7 acres to 5.5 acres — a staggering change from the 45 acres it once covered. 

Monarch habitats — both in their overwintering grounds and along their migratory routes — are under threat. Deforestation and both legal and illegal logging — often clearing land for agriculture and development — has taken out huge areas where they shelter in the winter in Mexico and California. The pesticides and herbicides used in intensive agriculture kill the monarchs as well as milkweed, on which they depend to survive. Climate change is making wildfires more frequent and destructive, taking out their territory. Higher temperatures can also trigger early migration, but the unprecedented temperatures can kill monarchs — millions, according to the IUCN. 

In July 2022, migratory monarchs, Danaus plexippus ssp. plexippus — a subspecies of the monarch butterfly, or Danaus plexippus — were placed on the “red list” and declared endangered by the International Union for Conservation of Nature (IUCN). However, in a reversal this September, they were downlisted to “vulnerable to extinction” — lower than “endangered” — on the list, based on data showing that population numbers were falling slower than originally thought. 

Among their other benefits to biodiversity, monarchs are important pollinators. About 75% of leading food crops depend on pollinators for survival, not to mention the many other plant species that contribute to diverse ecosystems and sustain wildlife populations. This is to say, we need pollinators like monarchs in order to grow the food we need. 

How to Help Monarchs During Migration Season

Plant Monarch-Friendly Species 

Not only does a native plant garden with diverse plants support a robust backyard ecosystem, it also helps pollinators! Monarchs — like many butterflies — benefit from native wildflowers that provide nectar, feeding on them and gathering energy for their long journey. Check out native wildflowers that suit your garden’s conditions and have varied blooming times so monarchs and other pollinators can feed all spring and summer long. The Xerces Society’s society puts out a Monarch Nectar Guide that will help you find the right plants for your area. 

Just as important as native flowers — and perhaps even more so — is planting milkweed. Adult monarchs exclusively lay their eggs on milkweed, and monarch caterpillars exclusively eat their leaves. With increasing development of once-open land, milkweed has fewer places to grow. It’s also targeted as a weed in agricultural lands and many urban/suburban areas. Luckily, it’s easy to plant, and easy to maintain in your own yard. Use the Xerces Society Milkweed Seed Finder to find a seed retailer, and look through their guides to determine the right native milkweed plants for your region. Follow the planting directions for each specific type of milkweed, as their needs vary. Generally, they do best when cold-treated and started indoors a few months before transferring outdoors after the last frost. Alternatively, you can collect seeds from native milkweed plants growing nearby. Before the pods burst in the fall, remove the seeds and store in a dry, cool area in an airtight container until you’re ready to plant. 

Don’t Rear Monarchs on Your Own 

Rearing monarchs on your own might seem like a helpful way to boost their populations, but it can actually do much more harm than good. The Xerces Society says that rearing monarchs in captivity can increase parasites, which are then spread to wild monarchs. Rearing over multiple generations can also decrease genetic diversity, which impacts the ability of species to develop resistance to disease, among other negative impacts. There’s been research to suggest that captive-bred monarchs have less fitness and are less successful at migration too. Instead, focus your efforts on other beneficial projects, like cultivating a pollinator-friendly garden!

Avoid Pesticides

Pesticides are a major contributor to declining monarch populations. Insecticides are indiscriminate, meaning that while they eliminate the bad bugs in your yard, they also eliminate many of the good ones – and monarchs are no exception. Other repellents like mosquito sprays are also toxic to monarchs. Instead, try organic gardening methods, focusing on natural methods of pest prevention, like planting marigolds and other pest-deterrent plants.

Protect Their Habitats and Take Action

Personal actions count for a lot, but collective and large-scale action is important as well. Vote for representatives who will protect undeveloped open space and nature/wilderness in all forms, and thus the habitats of both migrating and resident monarchs, along with all other kinds of migrating and resident animals and insects. This includes your local representatives too. Advocate for the natural areas where you live, whether it be a large city or a small town. 

Taking action for monarchs — and many other threatened species — can also mean making lifestyle changes. Like many environmental issues, the decline of monarch territories is highly connected to other issues of land use and climate change. Grasslands are important for milkweed, and thus monarch survival. However, grasslands are the fastest-disappearing ecosystem in North America, largely due to development and the conversion of land for agriculture. Thus, helping to save this land might look like reducing or eliminating meat from your diet, as a large proportion of farmland is used to grow crops to feed factory-farmed animals.