The African buffalo looks like a creature that should rule by force. A Cape buffalo bull can weigh up to 900 kilograms and carries a boss, a shield of fused bone across the forehead. Yet the herd is a matriarchy that settles its travel plans by something close to a vote. First described by the Swedish naturalist Anders Sparrman in 1779, Syncerus caffer is the only surviving species of its genus, split into four subspecies that range from the huge Cape buffalo of the open savanna to the small, reddish forest buffalo of about 265 kilograms.

This episode covers how the animal evolved, how it organizes itself, and how it shapes the land. Herds of a thousand or more break apart and rejoin with the seasons. Young males leave at four or five for bachelor groups, where rank is settled mostly by posture instead of combat. Feeding and ruminating fill 17 to 19 hours a day, and by mowing down tall, woody grasses the herds open the way for smaller grazers. The story also takes in the long contest with lions, the rinderpest catastrophe, and the buffalo’s place in African art and myth.

• During rest periods, adult females stand, gaze in a chosen direction, and lie back down. The herd moves the way most of them pointed, and a split vote can divide it for a few days.
• Genetic evidence indicates the small forest buffalo is closer to the older lineage, so the armored giant of the savanna is the newer model.
• A buffalo eats up to 15 kilograms of grass a day and needs about 45 liters of water every 48 hours, which ties herds to permanent water.
• Lions cannot break a buffalo’s neck, so a pride attacks from behind and suffocates it by clamping over the nose and mouth. Buffalo answer by backing into thorny thickets or mobbing the pride.
• Rinderpest, brought with European cattle in the 1890s, killed an estimated 95 percent of African buffalo. About 400,000 mature animals remain, and the species is listed as near threatened.