Dzanga Bai is a clearing of sand and mineral pools in the rainforest of the southwestern Central African Republic, and more than two hundred forest elephants can be on it at once. It is not a herd. Researchers have identified more than four thousand individual elephants here since 1990, and about eighty-five per cent of them come back; some have been logged more than a hundred times. They come from a huge stretch of forest that treats this one pan as a fixed address. What brings them is salt: mineral-rich water seeps up through the sand, carrying what leaves and fruit do not.
They come out of the tree wall at their own pace, a calf pressed to its mother's flank, and cross the open ground to the pits. The adults dig with trunks and tusks, and the holes they open become the calves' playground: a calf flops in sideways, rolls, and goes under while its mother drinks beside it. You watch from a platform at the edge of the trees. The bai does not perform on arrival. It fills and empties over hours, peaking in the middle of the afternoon, so what you do here is sit still for four hours. Between groups the clearing gives up its other users: grey parrots down for the same salts, forest buffalo and red river hogs at the edge. Much of what is said out there is pitched too low for your ears, rumbles that carry through the forest far past the clearing. The Ba'Aka lead everything else, taking three people at most off the trail, reading broken stems and last night's nests until a gorilla family is somewhere in the green ahead. A morning with their net hunt strings long nets between the trunks and drives the undergrowth towards them with shouting and song, and the women name the plants they use as medicine as you go. A female here has her first calf at about twenty-three and another every five or six years, so one that stops coming is not replaced within a human lifetime.