Behavioural observations from both the field and captivity indicate that same-sex sexual interactions are widespread throughout the animal kingdom, and occur quite frequently in certain non-human species. Proximate studies of these phenomena have yielded important insights into genetic, hormonal and neural correlates. In contrast, there has been a relative paucity of research on the evolutionary aspects. Homosexual Behaviour in Animals seeks to redress this imbalance by exploring animal same-sex sexual behaviour from an evolutionary perspective. Contributions focus on animals that routinely engage in homosexual behaviour and include birds, dolphin, deer, bison and cats, as well as monkeys and apes, such as macaques, gorillas and bonobos. A final chapter looks at human primates. This book will appeal to graduate students and researchers in evolutionary biology, biological anthropology, zoology, evolutionary psychology, animal behaviour and anyone interested in the current state of knowledge in this area of behavioural studies.
Part I. Introduction: 1. Homosexuality in animals. Topics, hypotheses, and research trajectories Volker Sommer and Paul L. Vasey; Part II. Non-primates: 2. Making the best of a bad situation. Homosociality in male greylag geese Kurt Kotrschal, Josef Hemetsberger and Brigitte Weiss; 3. Pink flamingos. Atypical partnerships and sexual activity in colonially breeding birds Catherine E. King; 4. Establishing trust. Sociosexual behaviour and the development of male-male bonds among Indian Ocean bottlenose dolphins Janet Mann; 5. Going with the herd. Same-sex interaction and competition in American bison Hilde Vervaecke and Catherine Roden; 6. Exciting ungulates. Male-male mounting in fallow, white-tailed and red deer Ludek Bartos and Jana Holeckova; 7. Frustrated felines. Sexual mounting between males in feral cats Akihiro Yamane; Part III. Primates: 8. The pursuit of pleasure. An evolutionary history of homosexual behaviour in Japanese macaques Paul L. Vasey; 9. Getting to know you. Female-female consortships in free-ranging rhesus monkeys Ellen Kapsalis and Rodney L. Johnson; 10. A wild mixture of motivations. Same-sex mounting in Indian langur monkeys Volker Sommer, Peter Schauer and Diana Kyriazis; 11. Playful encounters. The development of homosexual behavior in male mountain gorillas Juichi Yamagiwa; 12. Social grease for females? Same-sex genital contacts in wild bonobos Barbara Fruth and Gottfried Hohmann; 13. The evolution of male homosexuality and its implications for human psychological and cultural variations Dennis Werner; Part IV. Outlooks: Science and Beyond: 14. Where do we go from here? Research on the evolution of homosexual behaviour in animals Paul L. Vasey; 15. Against nature?! An epilogue about animal sex and the moral dimension Volker Sommer; Acknowledgements.
