Mate choice in female Taihangshan macaques ( Macaca mulatta tcheliensis ): Analysis based on mating patterns and paternity

Abstract

Mate choice is a key driver of reproductive fitness and a central topic in behavioral ecology. Although integrating behavioral observations with paternity analyses can provide powerful insights into mate choice, such combined approaches remain rare in non-human primates. Here, we conducted a one-year study on a free-ranging troop of Taihangshan macaques (Macaca mulatta tchelinesis) in northern China. Using behavioral observations and microsatellite genotyping, we examined female mating patterns using Friedman tests and compared offspring numbers across male rank/age groups using Kruskal-Wallis tests. Female copulations were biased to high-ranking and prime-aged males, and paternity was also biased towards these males. Notably, one low-ranking immigrant male and inferred extra-group males also achieved reproductive success. While male-male competition possibly contributed to the observed biases toward high-ranking/prime-aged males and the success of immigrant/extra-group males, our observations of sexual interference suggested that female choice also played an important role. Females likely preferred high-ranking males for direct benefits (e.g. resource access and protection) and prime-aged males for their higher reproductive capacity. In addition, novel (new immigrant or extra-group) males may also have a reproductive advantage, reflecting female strategies to increase offspring genetic diversity or avoid inbreeding. Our findings revealed complex female reproductive strategies and contribute to the understanding of sexual selection in primates.