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Updated: Aug 24, 2026

Blood Sampling and Hormone Measurement for Determining the Stage in the Ovarian Cycle in Marmosets
Published on: July 5, 2024
Ovarian cycle phase and same-sex mating behavior in Japanese macaque females
Ann C O'Neill1, Linda M Fedigan, Toni E Ziegler
1Laboratory for the Investigation of Ancient DNA, Department of Anthropology, University of Alberta, Edmonton, Canada.
Abstract:
The relationship of the ovarian cycle phase to same-sex mounting activity in adult female Japanese macaques (Macaca fuscata) was studied during the 1997/1998 mating season. Fecal samples were collected from eight female subjects two to three times per week and analyzed by enzyme immunoassay for fecal hormone levels. Hormone profiles of estrone (E1) and pregnanediol (PdG) were used to separate ovarian cycles into three phases: follicular, periovulatory, and luteal. Patterns of same-sex and heterosexual mounting behavior in the females were analyzed for phase variation during conceptive cycles. Same-sex mounting among female Japanese macaques occurred most frequently during the follicular and periovulatory phases of the cycle, and not at all during the luteal phase, paralleling the pattern found in heterosexual mounting behavior. These findings suggest a link between hormonal fluctuations and patterns of sexual mounting, regardless of whether the partner is of the same or opposite sex.
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