The phenomenon that some people in Brookings, Oregon, would later call a miracle began in early July 2019, when the same monarch butterfly appeared in Holly Beyer’s yard almost every day for two weeks. Beyer recognized it by a scratch on one wing. She and a friend named it Ovaltine, inspired by ovum, for the way it encrusted the milkweed in Beyer’s garden with eggs. Each off-white bump was no larger than the tip of a sharpened pencil. Clustered together on the green leaves, they looked like blemishes, as if the milkweed had sprouted a case of adolescent acne.

Brookings sits on Oregon’s rugged coast, and squarely within the monarch’s habitat. Every spring and summer, several generations of butterflies breed, lay eggs, and die, each in the span of about a month. The last generation of the year is different. Come fall, rather than produce offspring, it migrates south. Beyer, a petite retiree with a trace of red in her gray hair, is part of a local group who promote butterfly-friendly gardening practices—planting native flowers, for instance, and forgoing pesticides.

Most female monarchs disperse their eggs as widely as possible, but for unknowable reasons, Ovaltine laid almost 600 in Beyer’s yard. Under normal conditions, fewer than 5 percent of monarch eggs survive to adulthood. Beyer wanted the marvel she had witnessed from her deck to have a happier ending. She snipped the laden leaves and brought them inside, to shield the eggs from wind, rain, and predators. Before long she had hundreds of caterpillars, then hundreds of butterflies. She released them into the wild, and Brookings, with a human population of just 6,500, was suddenly ablaze with orange wings. A person could be taking the trash out or crossing a parking lot and see a flash, like a struck match, from the corner of their eye.

Soon the monarchs had blanketed Brookings in “the second eggsplosion,” as Beyer put it. “Every milkweed plant”—the only flora that monarch caterpillars eat upon hatching—“got egg-bombed.” Over the next several weeks, Beyer counted nearly 2,700 eggs in her yard. Based on other people’s reports from their own gardens, she estimates that there were 5,000 more across Brookings.

Beyer dutifully gathered the eggs laid on her property and put them in a maze of mesh crates she’d set up on the small deck of her 400-square-foot apartment. As the caterpillars hatched, she gave her life over to their care. The tiny creatures do nothing but eat and evacuate, and Beyer spent every day harvesting milkweed to go in one end and sweeping away the droppings that came out the other. “I would start at 10 a.m. and wouldn’t finish feeding them until six at night,” she told me. “I lost 15 pounds because I forgot to feed myself.”

A friend of Beyer’s sent out a grassroots SOS, begging anyone in Oregon with experience hand-rearing monarchs to come and take some of the remaining eggs off her hands. That’s how Amanda Egertson heard about the eggsplosion. A trained ecologist, Egertson is the stewardship director of a land trust in central Oregon. She lives in the city of Bend, almost 300 miles away from Brookings. She called her husband and asked if he could skip work for a day or two. They packed their kids into the car and started driving.

Waiting for them in Brookings was a makeshift incubator for 110 monarch eggs: a foil lasagna pan lined with damp paper towels to keep the milkweed leaves placed inside it from wilting. It would be up to Egertson to usher the butterflies into life. If she succeeded, the monarchs hatched under her care would be the first she’d seen that year. In the weeks leading up to her trip to Brookings, she’d scouted for flickers of orange as she traversed the land trust. For the first time she could remember, she hadn’t seen a single one.

While Egertson was retrieving the lasagna pan, I was a continent away, sitting for hours every day on my in-laws’ porch in Massachusetts. From there I could see thick patches of butterfly weed, a variety of milkweed that grows wild on their hilltop property. It was waist high in places, and covered in starburst bunches of brilliant orange flowers. Each tiny blossom had one row of tangerine petals stretching down and another row stretching up, like little dancers with raised arms. The plant is sometimes called orange glory, which suits it. When my husband’s father cut the field, he mowed carefully around the flowers. Once, he motioned me off the porch swing where I was reading to show me a monarch feeding on the blossoms.

The monarch (Danaus plexippus) is a large butterfly, and among the slowest moving in North America. It takes no special skill to spot one or to identify what you’ve seen. If you went to an American elementary school, you probably learned in science class how a monarch egg becomes a caterpillar becomes a chrysalis becomes a butterfly. Some lepidopterists (butterfly experts) disdain monarchs in the way that anyone with esoteric tastes looks down on what’s popular. “People call them the cockroaches of butterflies,” one scientist told me.

But the world has dulled your capacity for wonder if you cannot be awed by monarchs, which undertake one of the longest annual migrations of any insect on earth. A paperclip weighs a gram; a monarch weighs about half that. The thickness of a piece of paper is one-tenth of one-thousandth of a meter; the thickness of the monarch’s distinctive orange wings—veined in black and dappled with white spots at the edges—is measured in microns, or millionths of a meter. Monarchs can travel even on wings that appear too torn for flight, and scientists estimate that in good weather they can cover 30 miles or more in a single day. East of the Rockies, millions of butterflies migrate thousands of miles, from southern Canada to central Mexico, where oral traditions suggest that the incandescent insects have blanketed forests every winter for centuries. West of the Rockies, a smaller number of monarchs fly south as the weather cools and spend the winter huddled in trees on the central coast of California. No one knows how they find the groves to which they return every year.

The monarch was once as common as it is beautiful—the most ordinary of extraordinary things. As a child, I saw them all the time in the warm months, drinking from weedy flowers at the edges of cornfields. Now, though, the population is in precipitous decline. This is true all over North America, but especially out west, in places like Oregon and California. In 2018, a count of western monarchs turned up only 27,218, fewer than 1 percent of the number recorded in the mid-1980s. Worse still, that figure failed to clear an existential threshold of sorts: Ecologists had recently warned that the western monarch’s risk of extinction could intensify if the population fell below 30,000.

The causes of the decline are many and manmade: loss of habitat, increased use of pesticides, the acceleration of climate change. On the broadest scale, these forces overlap with the reasons that the island wheremy in-laws live floods more severely with every passing year. Visiting them last summer, I spent more time outside than I had since my childhood, but the pleasure of sunny days was darkened by dread. The monarchs in particular brought me back to a time before I knew about climate change or lived with the awareness that I might someday witness a mass extinction. The idea of a future without them started to represent everything I was frightened to live through.

It’s not news that our impending environmental cataclysm requires urgent action, especially by world leaders and fossil-fuel companies—people and entities with the power to fundamentally change the way we use our planet’s resources. The steps we can take as individuals won’t be sufficient; they won’t even be significant unless millions of people follow suit. For me at least, this made it hard to commit to even small forms of environmental action. I would attempt something—composting, or taking the bus more, or cutting meat out of my diet—only to find that it didn’t allay my sense that I was doing nothing. It was like trying to ride a bike when the gears wouldn’t catch. I wanted to push the pedal down and feel myself move.

I envied my father-in-law’s steady sense of purpose as he mowed around butterfly weed so that monarchs could feed on the flowers. It was a modest act of stewardship that brought him great satisfaction when butterflies landed on the patches of growth he’d conserved. I, too, wanted to do something that mattered in ways I could see and feel.

Near summer’s end, I read a news article in which a biologist made a case for monarch conservation that went beyond butterflies. Karen Oberhauser of the University of Wisconsin–Madison described monarchs as a flagship species, an animal that captures imaginations and induces people to care about its fate. “We’ve surveyed people and asked, ‘How much would you pay to save monarchs?’” Oberhauser said when I called her. “It’s up there with whooping cranes, polar bears, and wolves—all these charismatic vertebrates.” When people like my in-laws protect monarch habitat, they assist other species they may never have heard of. By extension, they support entire ecosystems. “On some days, I feel like maybe we won’t save monarchs, but if we try to save them, we’re going to do good for the world,” Oberhauser said.

Was this what I had been looking for—an animal to lend its shape to my formless sense of environmental grief? In the book What I Don’t Know About Animals, novelist and essayist Jenny Diski observes that humans have been turning animals into symbols ever since the beginning of language, employing them as tools “to think about anything and everything.” Maybe I could make monarchs my personal shorthand for something otherwise too large to grasp. I didn’t yet know about Beyer and Egertson, who were upending their lives with a feverish energy that comes from believing you can make a difference, but I had arrived at a similar idea: I hoped that, if I trained my attention on a single creature, I would figure out what it meant to do my part. Maybe fear of a loss specific enough to imagine would impel me to act. And once I started, maybe I wouldn’t stop.