A pair choice test to identify female mating pattern relative to ovulation in longtailed macaques, Macaca fascicularis

Abstract

Female mammals may exert choice for mates directly by mating selectively. Alternatively, females can mate promiscuously, allowing sperm competition and/or cryptic female choice to operate. Primate sexual behaviour is probably a compromise between conflicting male and female interests, so it may be important to examine female mating behaviour independently from male influence to better understand female mating strategies. To explore how female behaviour and ovarian cycle phase influence the choice and number of mates in female longtailed macaques, we conducted a pair-choice test where females had complete control over access to males. Subjects were six females and four males. Females were presented with a different pair of males twice a day. Each male was in an adjacent chamber. Females could enter freely and were allowed two entries per male pair. Entry and subsequent copulation with a male was defined as a choice with mating. Females saw each male every day; the males within a pair alternated in a fixed order. We related the females' mating pattern to the females' mating pattern to menstrual cycle stage and timing of ovulation, as determined from faecal progestogen profiles. Females chose and mated with males promiscuously in all periods of their menstrual cycle (prefertile, fertile and postfertile). Overall, females apportioned choices with mating and number of copulations evenly across males. In general, female preferences were not based on male dominance rank. Further investigation is needed to better understand the nature of mating preferences and the adaptive significance of promiscuity in female primates.