The monarch butterfly, perhaps the most recognizable butterfly in North America, is in trouble: since the mid-1990s, their population has declined 90 percent from its 20-year average, and their wintering colonies in Mexico now occupy the smallest amount of land they have since 1993. Illegal logging around their wintering sites in Mexico, as well as the loss of milkweed in the midwestern United States, threatens their magnificent migrations from Canada to Mexico—one of the most spectacular annual occurrences in the insect world. Earlier this year, the U.S. Fish and Wildlife Service announced that it would launch a year-long study into whether the monarch butterfly should be placed on the Endangered Species list, thus giving it federal protection.
"Over the last 20 years, we've noticed a decline in numbers," says Lauren Tuzzolino, who works in the Butterfly Pavilion at the National Museum of Natural History. "A lot of it is with habitat loss—they don't have the same resources for milkweed that they used to have." Milkweed is crucial to migrating monarchs because it provides the butterflies with a place to lay their eggs—and acts as a source of food for the caterpillars born from those eggs.
While their numbers are on the decline, the monarchs' migration is still a magnificent sight—and something that can be seen across thousands of miles. And, some say that encouraging tourism to monarch wintering spots, especially those in Mexico, might be a way to save the monarchs from doom.
"Most North American monarchs overwinter in the mountain forests of central Mexico, where the butterflies find exactly the environmental conditions that they need ... Although [it's] an oversimplification, the big problem is that the indigenous people ignore the central government and cut the forest to survive," says Robert Robbins, a research entomologist with the National Museum of Natural History. "The conservation goal is to increase the eco-tourism value of these areas as an alternate source of funds. To some extent, I am told that it is working, but perhaps not sufficiently well."
Although illegal logging and the loss of milkweed is contributing to the decline in monarch numbers, it's the monarch's migration that's the most threatened. "Its not that the species would die out, but the migration would end. The migration is an endangered phenomenon," Tuzzolino says. While it's unlikely that the monarch will disappear entirely, the loss of their migration would mean the disappearance of a biologically unique phenomenon—monarchs are the only known butterfly to make a two-way migration.
If you want to catch a glimpse of the endangered phenomenon, here are seven locations that boast large numbers of migratory monarchs. Want to help closer to home? Consider planting milkweed on your property, to give monarchs a place to stop on their migration. "I think day-to-day citizen science, whether it is being aware of the correct type of milkweed [to plant], or little things to raise awareness, is really important," Tuzzolino says.
Point Pelee National Park, Ontario, Canada
Though most ecotourism efforts focus on visiting monarchs at their wintering sites in Mexico, which are threatened by logging, the butterflies can be seen in large numbers as far north as Ontario and Quebec, where they feed on milkweed and breed. In 2008, the Canadian government deemed the monarch a species worthy of "special concern," due to its dwindling population numbers.
To see huge numbers of monarchs in Canada, head to Point Pelee National Park, in Ontario, where the butterflies live and breed from early spring to fall, when they begin their southward migration. Because the migration happens over such a considerable distance, butterflies look for shortcuts whenever they can, which is what makes Point Pelee such a desirable spot—located on a peninsula that juts into Lake Erie, the site gives thousands of monarchs a head-start on their southward journey. After following the shape of the peninsula, the butterflies will funnel to the tip of the point and wait for a breeze to help them begin their migration.