The Backyard Naturalist – There Be Dragons
The Curious Geography of Dragonfly Migrations
Driving somewhere with my kids, my older son noted an ant crawling across the dashboard, declaring it a stowaway. The ant roamed, probing the surfaces, and I watched it, thinking it was as good as dead. An ant alone, driven miles and miles from its colony, is as alive as a severed limb — that is, briefly, and in any meaningful sense of the word, not at all.
I’ve been taking an online course on the veterinary management of honeybees, and the instructor reminds us often that the creature we’re treating is the colony, not the individual bee. A colony can live for decades, though no single bee’s lifespan is close to as long. For this reason, she explains, killing a few bees to test for disease is less like sacrificing chickens from a flock, or cows from a herd, and more like drawing a blood sample from a cat; the individual cells in the blood are doomed to die, but their loss won’t trouble the cat, and we recognize the being they were drawn from to still be alive.
I found myself pondering the way some insects defy our traditional definitions of what a “being” is as I read about dragonfly migrations. Their travels are far less widely known compared to those of hawks, or monarch butterflies, but no less remarkable. These species move north in spring, often over great distances, and back south in fall. The mass movements of hawks is a spectacle, but dragonflies, undertaking flights of similar distance and duration, are small and solitary, and essentially unable to carry a tracking unit. For a long time, this meant no one knew the nature or extent of their peregrinations. A few years ago, a study of common green darners used the chemical signature in their wing tissue to determine where the animals had been. Like monarchs, it turns out, the migration of dragonflies is multigenerational. No single dragonfly makes it from the wintering grounds in Florida, or Texas, or Mexico, up to summer in Maine and then back down again. The process is stepwise; a dragon travels to the North come warm weather, lays eggs there, and dies. The next generation hatches in the North, and when cooler weather comes, heads to the South. Those females lay their eggs there and die. Those eggs hatch into a group of dragons that will not migrate at all, living out their lives and reproducing entirely in the South. Their offspring will begin the whole cycle again.
Dragonflies are not social or colonial like honeybees and ants, so it’s hard to argue that each dragon is a small part of a superorganism, as with those animals. But on the range maps of the darner migration, a thin margin along the Gulf Coast shows that the animals’ location in January expands and spreads up to the Canadian border by summer, then recedes again to gray as the mass of creatures migrates away from the cold in October. It reminds me of the tidal flow of breathing, the air we rely on flowing into us and out again, never becoming fully a part of us. In this pandemic, we are acutely aware of breath, of the line between the air itself and the person it keeps alive, of the stowaway virus it might usher in, and then out again into another body. The virus isn’t entirely part of our being, but the particles traverse our internal geography, reproduce there, then flow onward, the next iteration, the next body, the next. The fracturing of our social world as a result, the separation, the pain of amputated relationships, leaves me to wonder if we might not ourselves each be less dragonfly, more honeybee.