Male Dominance and Reproductive Success in a Captive Group of Rhesus Macaques (Macaca Mulatta)

Abstract

AbstractPaternity exclusion analysis was employed to estimate the reproductive success (RS) of 32 males who experienced at least one breeding season over the age of four years between 1977 and 1991 in a captive group of rhesus macaques (Macaca mulatta). Although three different males held alpha rank during the period, the male dominance hierarchy remained relatively stable even when the number of males was high. Average dominance rank and overall RS of males while in the group were strongly correlated. However, during most years the correlation between male dominance rank and RS was not statistically significant because males who achieved high rank 1)were those who experienced relatively high RS as lower ranking subadults and 2) maintained high dominance rank after experiencing a sustained decline in RS. Correlations between male dominance rank and RS were highest when the number of subadult males entering the dominance hierarchy was increasing and one or a very few males were least effective in monopolizing females. These results are not consistent with expectations based solely on the priority of access model of intrasexual selection. Female choice, as exemplified by the preference of females for mating with young males that are rising in rank, might also influence the evolution of social dominance in rhesus macaques.