Data from: Chimpanzee females queue but males compete for social status

Dominance hierarchies are widespread in animal social groups and often
have measureable effects on individual health and reproductive success.
Dominance ranks are not static individual attributes, however, but instead
are influenced by two independent processes: 1) changes in hierarchy
membership and 2) successful challenges of higher-ranking individuals.
Understanding which of these processes dominates the dynamics of rank
trajectories can provide insights into fitness benefits of within-sex
competition. This question has yet to be examined systematically in a wide
range of taxa due to the scarcity of long-term data and a lack of
appropriate methodologies for distinguishing between alternative causes of
rank changes over time. Here, we expand on recent work and develop a new
likelihood-based Elo rating method that facilitates the systematic
assessment of rank dynamics in animal social groups, even when interaction
data are sparse. We apply this method to characterize long-term rank
trajectories in wild eastern chimpanzees (Pan troglodytes schweinfurthii)
and find remarkable sex differences in rank dynamics, indicating that
females queue for social status while males actively challenge each other
to rise in rank. Further, our results suggest that natal females obtain a
head start in the rank queue if they avoid dispersal, with potential
fitness benefits.