Savannah elephant family dynamics: short- and long-term responses to environmental and social changes

Multilevel societies offer flexibility in short-term association patterns for individual members while retaining valuable long-term relationships with conspecifics. Using a long-term data set on free-ranging African elephants, Loxodonta africana , in Amboseli, Kenya, we illustrate the complexity of decisions about associates in elephant multilevel societies on annual and longer-term timescales, spanning over 50 years. We explore the social dynamics of elephant families and within-family associations in relation to (1) maternal kinship, (2) demographic processes within a family and (3) environmental conditions. Average matrilineal relatedness among adult females (9 or more years of age) within a maintained social unit (family) was estimated from observed pedigrees as 0.146, equivalent to the level of aunt–niece relatedness. As families increased in size through successful reproduction, relatedness declined and females made more individual choices about associates, reducing cohesion among females from the same family. Droughts also reduced family sociability. Matriarchs, defined as the oldest female in a family and its social centre, were a median of 39 years old at the start of their tenure and led their families for almost 20 years. Matriarch death tended to make families less cohesive in the short term but did not consistently lead to family breakdown.