The absence of strong tendencies to stratification and the type of ecological adaptation present acted to inhibit the development of strong authority patterns. Leadership over a large population, such as that exerted by Chief Washakie, was necessarily temporary in nature and was largely restricted to periods when people united for the common enterprises of war and buffalo hunting. During the summer and most of winter and spring a host of minor chiefs of varying influence and prestige were responsible for directing the activities of clusters of followers. Even war and the spring and fall hunts did not necessarily entail the participation of an entire tribe. The buffalo hunters frequently split into smaller hunting parties when out on the plains. And warfare, if offensive, usually was carried on by small raiding parties. Even in defensive warfare attacks were swift and without warning, and large numbers of people could not be gathered to repel the invaders. "Tribal" chiefs did exist in Idaho and Wyoming, but they exercised discontinuous influence on a group of followers, who might only infrequently all gather as a unit. And since it is impossible to isolate Shoshone or Bannock tribes as stable membership units, the great chiefs may be more profitably viewed as the men of highest prestige within a certain area. The positions of these leaders became more clearly defined in later times, when first traders and then government agents sought them out as representatives of their people. That the white man's image of the chieftaincy was erroneous may be seen in the examples cited of disaffection and the subsequent efforts of the agents to shore up the authority of their delegated chiefs. Chiefs acted in consultation with councils of distinguished men and lesser chiefs, and the familiar Plains role of camp announcer is also present among the Shoshone. The chief in any area achieved his status through general consensus and recognition of his high prestige. Generosity, wisdom, bravery, and skill in hunting were key criteria for the selection of headmen. The position was neither hereditary nor for life. Although it is not possible to speak of a chief being "deposed," many a chief was replaced by a man whose star was in the ascendancy. And it was also possible for two or three men to have almost equivalent claim to the role within the same district. Despite the nonhereditary nature of the office, we sometimes find it shared by brothers, or sometimes one brother succeeded another. Such cases may be explained as the result of general family prestige or of common upbringing and ideals of conduct.