Continuity and change in dominance relations among female baboons

Abstract

Female baboons, Papio cynocephalus, in Amboseli National Park establish linear dominance hierarchies in which maternal kin usually occupy adjacent ranks. Previous work had shown that few changes in the relative rank order of matrilines had occurred between 1971 and 1981 (Hausfater et al. 1982). During a 9-month period beginning in December 1982, the rate and magnitude of changes in matrilineal rank order accelerated. Major changes in the relative ranks of members of a few matrilines resulted in changes in the absolute ranks of females of all but one matriline. However, the ordering between many pairs of matrilines did not change and the genealogical structure of dominance relations was generally maintained. This brief period of rapid change was succeeded by a period of slow change and relative stability in dominance relations, lasting at least 27 months. Data from the 15-year period suggest that the rates of change in female dominance relations are variable: long periods of stability are sometimes punctuated by short periods of instability and change. No single explanation accounted for this variability.