ABSTRACT
The world of the horse is made up of a social order or dominance hierarchy. A mare's position is fairly constant throughout her adult life. There seem to be two critical ages, one at each end of her life, that control her rise and fall in the hierarchy. Sometime between the age of three and five most mares will move up in the hierarchy from the lower end of the pecking order where most of the young and old horses are found. Instead of the mares being randomized throughout the dominance hierarchy, the breeds tended to segregate with a majority of the thoroughbred mares at the top and the quarter horse mares at the bottom. Early weaning studies in some mammalian species have shown that individuals mature physically but lack the proper socialization to become normal adults. The mares within the herd have a social order, or ranking.
