Bruce Bagemihl writes that the presence of same-sex sexual behavior was not officially observed on a large scale until the 1990s due to possible observer bias caused by social attitudes towards LGBT people, which made homosexuality in animals a taboo subject.[3][4] He devotes three chapters, "Two Hundred Years at Looking at Homosexual Wildlife", "Explaining (Away) Animal Homosexuality", and "Not For Breeding Only" in his 1999 book Biological Exuberance to the "documentation of systematic prejudices" where he notes "the present ignorance of biology lies precisely in its single-minded attempt to find reproductive (or other) "explanations" for homosexuality, transgender, and non-procreative and alternative heterosexualities.[5] Petter Bøckman, academic adviser for the Against Nature? exhibit, stated "[M]any researchers have described homosexuality as something altogether different from sex. They must realise that animals can have sex with who they will, when they will and without consideration to a researcher's ethicalprinciples". Homosexual behavior is found amongst social birds and mammals, particularly the sea mammals and the primates.[4]
Animal sexual behavior takes many different forms, even within the same species and the motivations for and implications of their behaviors have yet to be fully understood. Bagemihl's research shows that homosexual behavior, not necessarily sexual activity, has been documented in about 500 species as of 1999, ranging from primates to gut worms.[3][6] Homosexuality in animals is controversial with some social conservatives because it asserts the naturalness of homosexuality in humans, while others counter that it has no implications and is nonsensical to equate animal behavior to morality.[7][8]
Animal preference and motivation is inferred from behavior, thus homosexual behavior has been given a number of terms over the years. Modern research[9][10][11][12] applies the term homosexuality to all sexual behavior (copulation, genital stimulation, mating games and sexual display behavior) between animals of the same sex.
Ugandan kob - "Female kob perform oral sex on each other and even stroke each other's vulvas with their forelegs. They may exhibit urolagnia during sex, one female will urinate while the other sticks her nose in the stream."[1][14]
Harrold, Max (16 February 1999). "Creature Comforts". The Advocate. No. 779. pp. 61–62. Retrieved 10 March 2018. In his news book, Biological Exuberance: Animal Homosexuality and Natural Diversity ... author Bruce Bagemihl portrays an animal kingdom that embraces a whole spectrum of sexual orientations ... [and] paints a complex mosaic that resembles humanity ... At 751 pages and with photos and documentation of homosexual behaviour in more than 450 species of mammals, birds, repties, and insects, Biological Exuberance brings the dusty facts to light as Bagemihl deconstructs the all-heterosexual Noah's Ark we've been sold.
Liggett, Dave; Columbus Zoo and Aquarium staff. "African Forest: Bonobo". Columbus Zoo and Aquarium. Archived from the original on 2 June 2002. Retrieved 14 November 2011. ...frequent sex (including male-to-male and female-to-female) characterize bonobo society.
Roselli, Charles E., Kay Larkin, John A. Resko, John N. Stellflug and Fred Stormshak (2004). "The Volume of a Sexually Dimorphic Nucleus in the Ovine Medial Preoptic Area/Anterior Hypothalamus Varies with Sexual Partner Preference". Endocrinology, Department of Physiology and Pharmacology, Oregon Health & Science University (C.E.R., K.L., J.A.R.), Portland, Oregon; Department of Animal Sciences, Oregon State University (F.S.), Corvallis, Oregon; and Agricultural Research Service, United States Sheep Experiment Station (J.N.S.), Dubois, Idaho, Vol. 145, No. 2. Retrieved on 10 September 2007.
Schaller, G. B. (1972). The Serengeti Lion; University of Chicago Press.
Smith, Dinitia (7 February 2004). "Love That Dare Not Squeak Its Name"New York Times. Retrieved on 10 September 2007. Reprinted as "Central Park Zoo's Gay Penguins Ignite Debate", San Francisco Chronicle.
^ ab"Gay Animals: Alternate Lifestyles in the Wild | Live Science". livescience.com. Live Science. 20 September 2011. Archived from the original on 18 June 2024. Retrieved 30 August 2024. Homosexuality has been documented in more than 450 species of vertebrates signaling that sexual preference is biologically determined in animals.
^
Solimeo, Luiz Sérgio (18 March 2004). "Defending a Higher Law"(PDF). The American TFP. Archived(PDF) from the original on 24 July 2024. Retrieved 30 August 2024.
^Bagemihl (1999) pages 276–279. Excerpt from the book: Common Chimpanzees engage in full mouth-to-mouth contact[...] Oral sex of various kinds also occurs in a number of species[, for example] cunnilingus in Common Chimpanzees[...] In [...] Common Chimpanzees, individuals often rub their anal and genital regions together[...] Other [...] forms of "manual" stimulation include [...] anal stimulation and penetration with fingers by male Common Chimpanzees.
^Juichi Yamagiwa (1987). "Intra- and inter-group interactions of an all-male group of virunga mountain gorillas (Gorilla gorilla beringei)". Primates. 28 (1): 1–30. doi:10.1007/BF02382180. S2CID24667667.
^Pengzhen Huang; Xin He; Endi Zhang; Min Chen (2017). "Do same-sex mounts function as dominance assertion in male golden snub-nosed monkeys (Rhinopithecus roxellana)?". Am J Primatol. 79 (5): e22636. doi:10.1002/ajp.22636. PMID28103402. S2CID3875410.