Female fertile phase synchrony, and male mating and reproductive skew, in the crested macaque

James P Higham,Dyah Perwitasari-Farajallah,Antje Engelhardt,Michael Heistermann,Anja Widdig,Muhammad Agil

doi:10.1038/s41598-021-81163-1

Abstract

High social status is the primary determinant of reproductive success among group-living male mammals. Primates living in multimale–multifemale groups show the greatest variation in the strength of this link, with marked variation in reproductive skew by male dominance among species, dependent on the degree of female fertile phase synchrony, and the number of competing males. Here, we present data on two groups of wild crested macaques (Macaca nigra), living in the Tangkoko Reserve, Sulawesi, Indonesia. We investigated male monopolization of fertile females in 31 cycles of 19 females, and genetic paternity of 14 offspring conceived during the study period. We show that female fertile phase synchrony was low, that females had few mating partners in their fertile phase, and that dominant males monopolized a high proportion of consortships and matings, resulting in marked and steep mating and reproductive skew. We conclude that female cycle asynchrony provides the opportunity for strong direct male–male competition in crested macaques, resulting in monopolization of females by dominant males, consistent with their marked sexual dimorphism. Our study provides a test of the underlying factors that determine the relative occurrence and strength of different mechanisms of sexual selection, and the phenotypes that evolve as a result.

Highlights

Key measures of this degree of monopolization include the number of different partners that a female mates with during the cycle, (and especially during fertile phases), the degree of mating skew by male dominance rank, and reproductive skew
We studied two groups of crested macaques between 2006 and 2007 in the Tangkoko Reserve, North Sulawesi, Indonesia
The factors influencing female fertile phase synchrony in nonhuman primate populations are number of females, combined with the degree of breeding seasonality[7,8,10], with breeding seasonality in turn often thought to depend on seasonality in the environmental

Summary

Introduction

Key measures of this degree of monopolization include the number of different partners that a female mates with during the cycle, (and especially during fertile phases), the degree of mating skew by male dominance rank, and reproductive skew. We assess the level of female cycle synchrony, the extent to which males, especially the alpha male, are able to monopolize female fertile periods, and the extent of male mating and reproductive skew, in a wild population of one species of Sulawesi macaques, the crested macaque (M. nigra).

Results

Conclusion