One of the joys of fall when I was growing up was getting to experience the monarch migration. With the first hint of cool in the air, we’d start to notice individual monarchs flying low in a southerly direction. Soon, there would be thousands, millions of them, in huge meandering rivers rolling southward, high in the sky. I remember one evening in particular; a fair number came down to roost in our neighbor's oak, turning the whole tree orange with a cover of fluttering wings.
Monarchs, a North American original, have been a part of this land for nearly 2 million years. From their epic migration, down to their eating habits, they are creatures of extremes. Each year, hundreds of millions of monarchs (most of the world's monarch population) overwinters in Central Mexico within an area that currently encompasses only about 10 acres. In March, they head north and spread out across the southern United States, where they lay eggs and then die. After hatching, the new generation continues the migration as far as southern Canada. Two more brief generations are born and come to an end during the summer. The fourth generation completes the circle. Born in August, they migrate all the way back to those 10 acres in Mexico to spend the winter. This is a trip of 3,000 miles for some of them. Almost unbelievably, fluttering monarchs have been known to cover 50, 100 and sometimes more than 200 miles of this journey in a single day.
Adult monarchs feed on nectar from wildflowers, but they lay their eggs on the underside of native milkweed leaves. Milkweed plants produce a gummy, toxic sap for their own protection. As they mature, monarch caterpillars develop the ability to eat whole milkweed leaves by ingeniously chewing through the veins at the base of the milkweed leaf in order to cut off the flow of this sap. The toxins that they do ingest help protect them from some predators and disease. Out of one hundred eggs, only one or two will make it to adult butterflies. Adult monarchs leave the milkweed plant behind for a diet of nectar, but are still protected by the toxins they ingested as caterpillars, concentrating them in their wings, where predators are most likely to attack.
Through the warm season, monarchs are continuous visitors at Nan Awaya Farm. We took the image at the top of this post just last week. It shows a fairly mature monarch caterpillar enjoying a green milkweed plant. During the fall migration, we may see as many as 100 monarchs a day in our pastures, fueling up on swamp sunflower on the journey to Mexico. We’ve never seen the thousands of monarchs like I did as a kid in the 80s and 90s, though.
I had a general idea that this amazing native creature was in trouble, like many others. Watching a virtual presentation at work yesterday, a slide came across the screen, giving 2:1 odds that the monarch will be extinct within the decade. That landed like a punch to the stomach. A frantic search showed me that while this stat is a bit misleading, reality is not much better. The monarch might have 20 years left as a legitimate wild species. I learned that in the interval between when the monarchs roosted in our neighbor's tree (mid-90s) and the year that Amy and I started Nan Awaya (2015), the world's main population shrunk by 90%. Many things are killing these remarkable creatures, highways, extreme weather events, invasive plants, even climate change altering the chemistry of native milkweed plants in ways that can make them toxic to the caterpillars. However, the main culprit is a change in farming.
In the 1990s, farmers across the Midwest began planting varieties of corn and soybean that have been genetically engineered to tolerate glyphosate herbicide. These fields are now sprayed with this potent poison, killing the milkweed plants that used to grow between the crop rows. 130 million acres of monarch habitat disappeared almost overnight. People who study the monarch say that to rebuild the population to the point that it would be safe from extinction would require planting 1.5 billion stocks of native milkweed across the Midwest.
Three species of milkweed grow at Nan Awaya, but all together they number only in the hundreds of stocks. This winter and spring, we planted thousands of patches of native prairie seeds out in several of our pastures. We bought some milkweed seeds to go with them. We were so busy planting everything else, though, that by the time we got to the milkweed seed, it was too far along in the season to plant it. Now, it's too late.
"Too late," is exactly what came to mind when I heard those odds on the monarch's extinction. Even if every inch of Nan Awaya farm were planted in nothing but milkweed, it wouldn't amount to one millionth of what it would take to ensure the return of those rivers of monarchs rolling high through the fall sky. An effort to support the web of life around oneself is almost always worthwhile, though, even if the effort can only be small.
Even now, it's not too late to make a real difference. A number of individuals and organizations are passionately working to try to save the monarch. If you, like us, have a renewed determination to get some more milkweed growing on this continent during this next planting season, seeds and even free plants are available here. As little as a few plants in a suburban yard might help a monarch, or they just might help encourage a member of the upcoming human generation to be a better land steward than our current generation has been so far.