Reproductive activity in relation to male dominance and the likelihood of ovulation in rhesus monkeys

Summary

Data on reproductive activity in one group of free-ranging Macaca mulatta were analysed in an attempt to assess the explanatory power of male dominance for mate selection when male reproductive performance is weighted in relation to the likelihood of ovulation and conception. In the present study, ovulation was assumed to have taken place during the four-day period preceding the ‘attractiveness breakdown’, that is, the moment in the menstrual cycle presumed to coincide with the onset of the luteal phase, the diagnostic criterion being the termination of consorting activity.

Positive correlations were found between the dominance rank of males and both their copulatory frequencies and the time which they spent consorting during ovulatory periods. However, the comparison of the data with the predictions of a version of Altmann's (1962) ‘priority of access model’ shows that male rank does not explain all the variance in male reproductive activity. Deviations due to male abstention, male selectivity and female choice are discussed in the context of a number of asymmetries in the competitive ability of males (other than dominance) and in payoff from consorting. Female choice appeared to provide a payoff asymmetry which could not be easily overcome by the rebuffed suitor. This suggests that the observed positive correlation between male rank and reproductive performance resulted from male-male competitive interactions acting concurrently with the capacity of males to influence female choice (e.g. through interferences in the consortships of lower-ranking males).