The arctic tern, a sleek gray-and-white bird with a wide wingspan, black-capped head, and a body scarcely bigger than my fist, migrates every year from the Arctic to Antarctica and back. Coasting on air currents, terns snatch fish from the ocean and eat, sleep, and mate on wing. One tagged bird tracked nearly 60,000 miles in its annual migration—a distance equal to flying twice around the belly of the earth.
How birds like the arctic tern navigate these earth-spanning flights remains beyond the full understanding of science. Some birds seem to navigate by scent. Scientists have discovered iron-rich cells in the heads and beaks of other birds that they assume orient birds toward the earth’s magnetic poles. Most recently, scientists discovered a certain protein in the eyes of zebra finches that interacts with light in a way that allows them, scientists surmise, to see the earth’s magnetic fields.
Human beings cannot see these fields, and even our approximations are chaotic and strange. In computer simulations, geomagnetic field lines in neon colors tangle and splay outward, clustered generally around what we know as our North Pole and our South Pole.
Birds’ eyes may serve as a wayfinder, National Geographic notes, but this only indicates direction—to find their place on this vast earth, birds also need a map.
Evidence suggests that birds, like ancient sailors, orient themselves by the stars. In a classic study, birds caged outdoors, able only to look up, still hopped southward in the fall months and northward in the spring. The birds were then held in a planetarium, constellations projected on the ceiling. When the stars were reversed, previously northbound birds turned south, straining toward their false north star.
Birds’ remarkable migration is so difficult to understand precisely because it depends on this combination of complex senses. Birds feel the pull of the compass, and they also cast their eyes upward for a map.
We would be wise to do this too.
Where does our earth’s magnetic field draw us? I have followed mine across borders, unable sometimes to name the life I chase, only when I know I am drawing closer. In learning, in listening, in standing up for others or just buying them groceries, I feel oriented correctly—perhaps still distant from the place I hope to land, but on my way.
I find my bearings, meanwhile, in the fixed points of light around me. Activists and movements challenged dehumanizing systems long before they made headlines. I look up: their stars intersect in constellations of experience. As I keep them in my line of sight, the pull I feel takes shape and direction.
It takes both a compass and a map to find our way. Let us sense, like the birds, our direction in this world; with the stars, our place and path in it.
Katerina Parsons (’15) lives in Washington D.C., where she works in advocacy at Mennonite Central Committee’s Washington office and studies international development at American University’s School of International Service. She spends a lot of time thinking about US policy towards Central America and North Korea, writing, singing, and searching for the city’s best pupusas (suggestions welcome).