title: Female homosexual behavior and inter-sexual mate competition in Japanese macaques: possible implications for sexual selection theory.
abstract: In this paper, we review research related to female homosexual behavior in Japanese macaques (Macaca fuscata), including our 20-year program of research on this species. Multiple lines of evidence indicate that female homosexual behavior in this species is sexually motivated. In contrast, many sociosexual hypotheses have been tested in relation to female homosexual behavior in Japanese macaques, but none have been supported. Female Japanese macaques sometimes engage in same-sex sexual activity even when motivated opposite-sex alternatives are available. Within this context of mate choice, males compete inter-sexually for opportunities to copulate with females above and beyond any intra-sexual competition that is required. Anecdotal evidence suggests that inter-sexual competition for female sexual partners has been observed in a number of other species, including humans. At present it is unclear whether inter-sexual competition for sexual partners influences patterns of reproduction. Our understanding of sexual selection and the evolution of mating systems may be improved by investigating whether inter-sexual mate competition influences the acquisition and maintenance of reproductive partners in those species in which such interactions occur.
authors.affiliation: Department of Psychology, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada. Electronic address: paul.vasey@uleth.ca.
authors.forename: Paul L
authors.initials: PL
authors.lastname: Vasey
authors.affiliation: Department of Psychology, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Leca
authors.affiliation: Department of Psychology, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada.
authors.forename: Noëlle
authors.initials: N
authors.lastname: Gunst
authors.affiliation: Gender Identity Service, Centre for Addiction and Mental Health, Toronto, Ontario M6J 1H4, Canada.
authors.forename: Doug P
authors.initials: DP
authors.lastname: VanderLaan
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002755:Choice Behavior / Q000502:physiology*; D003163:Competitive Behavior / Q000502:physiology*; D005260:Female; D006716:Homosexuality; D008252:Macaca fascicularis / Q000502:physiology*; D008297:Male; D012726:Sexual Behavior, Animal / Q000502:physiology*
keywords: Female homosexual behavior; Inter-sexual mate competition; Japanese macaques; Sexual selection