The chapter involves review of current knowledge of behaviour in wild equid species regardless whether the studies dealt with wild, feral or captive populations. The chapter starts with topics of basic ethology like perception, time budget, and cognition. Neveretheless, most parts are devoted to the current topis of behavioural ecology like communication, affiliative, agonistic, and reproductive behaviour. Within these topics, the roles of social network, play, leadership, hierarchy, and suckling behaviour are emphsized.