The line appeared on the horizon as a gray thread on a pale green quilt, but as the plane flew closer, it became a column of a few hundred animals, winding across the plain. “Wildebeest,” Charlie shouted over the drone of the engine. “It’s a small group.” We were north of Tanzania’s Ngorongoro Crater, and since it was March, we knew the wildebeests would soon be moving northwest, up through Serengeti National Park and into Kenya.
And there they were, in a perfectly straight, nose-to-tail convoy. I could make out their curved horns and long heads nodding up and down as they trudged through the morning sun. Several calves pressed against their mothers’ flanks.
For thousands of years, wildebeest herds have journeyed through the greater Serengeti ecosystem in a clockwise circuit—each animal meandering roughly 1,750 miles, the distance from Portland, Maine, to Key West, Florida—following the rains, grazing on the grasses, fertilizing the land, becoming food for the predators. And here, treading the timeless trail of its ancestors, this herd was headed northwest.