For days, it watched as the strange object heaved up and down in the ocean, tossed mercilessly by the wind and the waves. Once or twice, the vessel nearly smashed into a reef, which might have ended our story. Yet somehow—whether through destiny, as some would later proclaim, or dumb luck—it drifted into an inlet, off the southeastern coast of Brazil, where several inhabitants laid eyes upon it.

More than fifty feet long and ten feet wide, it was a boat of some sort—though it looked as if it had been patched together from scraps of wood and cloth and then battered into oblivion. Its sails were shredded, its boom shattered. Seawater seeped through the hull, and a stench emanated from within. The bystanders, edging closer, heard unnerving sounds: thirty men were crammed on board, their bodies wasted almost to the bone. Their clothes had largely disintegrated.

Sandhill cranes are monogamous birds; during courtship, the male valiantly tosses vegetation or mud into the air and fans its wings above the body, before dancing with abandon and letting out a unison call. Then the pair throw their heads back—the male at a deeper angle—and the female lets out two calls for each call the male emits. Lifelong pairs rely on this short, sharp unison call for relationship maintenance—it’s a pair’s shorthand to stay connected, or to alert a mate to a threat in their breeding area. Dancing, too, is used not only in courtship rituals, which are said to be infrequent in lifelong pairs, but also as a communal activity. These cranes have at least ten different types of dances and as many calls; their dances are so lively, with leaps, bows, and head pumps that I wonder whether this is why a group of cranes is also referred to as a dance or swoop of cranes.