People who make their living by tending herds of large animals. The species of animals vary with the region of the world, but they are all domesticated herbivores that normally live in herds and eat grasses or other abundant plant foods (e.g., cattle, horses, sheep, reindeer). Traditional pastoralists are essentially subsistence herders who form small-scale societies. There are essentially two forms of pastoralism--nomadism and transhumance.