Behavior of Feral Horses and Ponies

An overview of the behavior of feral horses and ponies is presented. Three major types of social groups have been described: 1) harem groups, 2) multiple male and female groups and 3) bachelor male groups. A herd has been proposed as another type of social structure consisting of groups of horses that follow similar movement patterns within a common home range. Horses and ponies usually occupy home ranges (undefended, nonexclusive areas). However, two studies reported horses occupying territories (defended, exclusive areas). The number of animals that occupies a particular home range and their movements within the home range are strongly influenced by food quantity, quality and seasonal changes. Group encounters are frequent because home ranges usually overlap, and group integrity is maintained by the male(s) of the group. Horses and ponies have intragroup and intergroup dominance hierarchies. Recent findings have indicated that stallions are not always dominant over mares. Most studies of mating behavior suggested large variance in male reproductive success, because most of the matings were performed by harem or dominant group males. In contrast, males in multiple male and female groups in the Red Desert of Wyoming shared mating privileges. The number of horse and pony foals as a percentage of the total population in each study ranged from 13 to 23%. Most foals were born during April to June. Mortality was highest among foals, while some feral horses lived 15 or more yr. Horses and ponies have been reported to spend a great deal of time and effort on fecal and urine marking.