This article contains a list of animals displaying homosexual behavior. See also Homosexual behavior in animals.

Roy and Silo, two Central Park Zoo male Chinstrap Penguins similar to those pictured, became internationally known when they coupled and later were given an egg that needed hatching and care, which they successfully did.^[1]

This list includes animals (birds, mammals, insects, fish etc.) for which there is documented evidence of homosexual or transgender behavior of one or more of the following kinds: sex, courtship, affection, pair bonding, or parenting, as noted in researcher and author Bruce Bagemihl's 1999 book Biological Exuberance: Animal Homosexuality and Natural Diversity.

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 making the homosexual theme taboo.^[2][3] Bagemihl 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.^[4] Petter Bøckman, academic adviser for the Against Nature? exhibit states

"[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 ethical principles".

Homosexual behavior is widespread amongst social birds and mammals, particularly the sea mammals and the primates.^[3]

"No species has been found in which homosexual behaviour has not been shown to exist, with the exception of species that never have sex at all, such as sea urchins and aphids. Moreover, a part of the animal kingdom is hermaphroditic, truly bisexual. For them, homosexuality is not an issue."

—Petter Bøckman^[3]

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 sex, has been observed in close to 1500 species, ranging from primates to gut worms, and is well documented for 500 of them.^[5][6]

Homosexuality in animals is seen as controversial because some assert it points to the naturalness of homosexuality in humans, while others counter that it has no implications and is nonsensical to use animal behavior to justify what is or is not immoral.^[7][8] Animal preference and motivation is always inferred from behavior. Thus homosexual behavior has been given a number of terms over the years. The correct usage of the term homosexual is that an animal exhibits homosexual behavior, however this article conforms to the usage by modern research^{[9][10][11][12]} applying the term homosexuality to all sexual behavior (copulation, genital stimulation, mating games and sexual display behavior) between animals of the same sex.

This is an incomplete list, which may never be able to satisfy certain standards for completion. You can help by expanding it with reliably sourced additions.

[edit] Selected images

Three species of Cnemidophorus.

The asexual, all-female Whiptail lizard species Cnemidophorus neomexicanus (center), which reproduces via parthenogenesis, is shown flanked by two sexual species having males, C. inornatus (left) and C. tigris (right). Research has shown that simulated mating behavior increases fertility for Cnemidophorus neomexicanus. One female lies on top of another, playing the role of the male, the lizard that was on bottom has larger eggs. The lizards switch off this role each mating season.^[13]

The head of a Darner dragonfly (Basiaeschna janata).

Male homosexuality has been inferred in several species of dragonflies. A survey of damsel and dragonflies reveals characteristic cloacal pincher mating damage in 20–80 percent of the males, indicating a fairly high occurrence of sexual coupling between males.^[14][15]

[edit] Mammals

[edit] Selected mammals from the full list

African Elephant[16] Brown Bear[17] Brown Rat[18] Buffalo[19]

Caribou[20] Cat (domestic)[21] Cheetah[22] Common Dolphin[23]

Common Marmoset[24] Common Raccoon[25] Dog (domestic)[26] European Bison[27] Prea[28]

[edit] Birds

Main article: List of birds displaying homosexual behavior

[edit] Selected birds from the full list

Chicken (Domestic)[29] Common Gull[30]

Emu[31] King Penguin[32]

[edit] Fish

Arctic Grayling (Thymallus arcticus) leaping for a fly fisherman's bait. Research going back to the 1950s has shown both male and female Graylings exhibit homosexual behavior.^[33]

• Amazon molly^[34]
• Blackstripe topminnow^[35]
• Bluegill Sunfish^[36]
• Char^[37]
• Grayling^[33]
• European Bitterling^[38]
• Green swordtail^[39]
• Guiana leaffish^[40]
• Houting Whitefish^[41]
• Jewel Fish^[42]
• Least Darter (Microperca punctulata)^[43]
• Mouthbreeding Fish sp.^[44]
• Salmon spp.^[45]
• Southern platyfish^[46]
• Ten-spined stickleback^[47]
• Three-spined stickleback^[47]

[edit] Reptiles

Anole sp.[48] Bearded Dragon[49] Broad-headed Skink[50] Checkered Whiptail Lizard[49] Chihuahuan Spotted Whiptail Lizard[49] Common Ameiva[49] Common Garter Snake[51] Cuban Green Anole[48] Desert Grassland Whiptail Lizard[49] Desert Tortoise[52] Fence Lizard[49] Five-lined Skink[50] Gopher (Pine) Snake[53] Green Anole[48] Inagua Curlytail Lizard[49]

Jamaican Giant Anole[48] Laredo Striped Whiptail Lizard[49] Largehead Anole[48] Mourning Gecko[54] Plateau Striped Whiptail Lizard[49] Red Diamond Rattlesnake[55] Red-tailed Skink[50] Side-blotched Lizard[49] Speckled Rattlesnake[56] Water Moccasin[57] Western rattlesnake (Crotalus viridis)[58] Western Banded Gecko[54] Whiptail Lizard spp.[49] Wood Turtle[59]

[edit] Amphibians

• Appalachian Woodland Salamander^[60]
• Black-spotted Frog^[61]
• Mountain Dusky Salamander^[60]
• Tengger Desert Toad^[62]

[edit] Insects and other invertebrates

Acanthocephalan Worms[63] Alfalfa Weevil[64] Australian Parasitic Wasp sp.[65] Bean weevil sp.[66] Bedbug and other Bug spp.[67][68] Blister Beetle spp.[69] Blood-flukes (Schistosoma)[70] Blowfly[71] Box Crab[72] Broadwinged Damselfly sp.[73] Cabbage (Small) White (Butterfly)[74] Checkerspot Butterfly[74] Clubtail Dragonfly spp.[75] Cockroach spp.[76] Common Skimmer Dragonfly spp.[75] Creeping Water Bug sp.[77] Cutworm[78] Digger Bee[79] Dragonfly spp.[75] Eastern Giant Ichneumon (wasp)[65] Eucalyptus Longhorned Borer[80] Field cricket sp.[81] Flour beetle[82] Fruit Fly spp.[83] Glasswing Butterfly[74] Grape Berry Moth[84] Grape Borer[80] Green Lacewing[85] Harvest Spider sp.[86] Hawaiian Orb-Weaver (spider)[86] Hen Flea[87] House Fly[88] Ichneumon wasp sp.[65] Incirrate Octopus spp.[72] Japanese Scarab Beetle[89] Jumping spider sp.[86] Larch Bud Moth[84] Large Milkweed Bug[90] Large White (Pieris brassicae)[91] Long-legged Fly spp.[92] Mazarine Blue[93] Mediterranean Fruit Fly[83] Mexican White[94] Midge sp.[92]

Male flour beetles are believed by scientists to engage in gay sex to practice mating as well as rid themselves of "old, less effective" sperm.[82] Migratory locust[95] Mite sp.[92] Monarch Butterfly[74] Narrow-winged Damselfly spp.[73] Parsnip Leaf Miner[92] Pomace fly[92] Queen Butterfly[74] Red Ant sp.[92] Red Flour Beetle[96] Reindeer Warble Fly (Hypoderma tarandi)[92] Rose Chafer[92] Rove Beetle spp.[97] Scarab Beetle (Melolonthine)[98] Screwworm Fly[92] Silkworm Moth[84] Sociable Weaver[92] Southeastern Blueberry Bee[79] Southern Green Stink Bug[99] Southern Masked Chafer[92] Southern One-Year Canegrub[92] Spreadwinged Damselfly spp.[73] Spruce Budworm Moth[84] Stable Fly sp.[92] Stag Beetle spp.[100] Tsetse Fly[92] Water Boatman Bug[101] Water Strider spp.[102]

[edit] See also

• Against Nature?, an exhibit at the University of Oslo's Natural History Museum that took place until August 19, 2007.
• Anthropomorphism
• Behavioral ecology is the study of the ecological and evolutionary basis for animal behavior
• Biodiversity
• Bioethics
• Biology and sexual orientation
• Ethology is the scientific study of animal behavior, and a branch of zoology; cognitive ethology fuses cognitive science and classical ethology to observe animals under more-or-less natural conditions
• Evolutionary biology
• Feral child
• Innate bisexuality
• List of important publications in biology
• Sexual selection

[edit] Bibliography

• 365 Gay.com. (11 February 2005). Gay Penguins Resist 'Aversion Therapy'. Retrieved on 10 September 2007.
• Bagemihl, Bruce (1999). Biological Exuberance: Animal Homosexuality and Natural Diversity. St. Martin's Press ISBN 0-312-19239-8
• Caramagno, Thomas C (2002). Irreconcilable Differences? Intellectual Stalemate in the Gay Rights Debate; Praeger/Greenwood, ISBN 0275977218.
• Cooper, J.B. "An Exploratory Study on African Lions" in Comparative Psychology Monographs 17:1-48.
• Cziko, Gary (2000) The Things We Do: Using the Lessons of Bernard and Darwin to Understand the What, How, and Why of Our Behavior; MIT Press, ISBN 0262032775.
• de Waal, Frans B. M. (2001) The Ape and The Sushi Master: Cultural Reflections by a Primatologist; Basic Books (chapter Bonobos and Fig Leaves).
• Dunkle, S.W. (1991), Head damage from mating attempts in dragonflies (Odonata:Anisoptera).Entomological News 102, pp. 37-41. Retrieved on 12 September 2007.
• Eaton, R. L. (1974). "The Biology and Social Behavior of Reproduction in the Lion" in Eaton, ed. The World's Cats, vol. II; pp.3-58; Seattle.
• Forger, Nancy G., Laurence G. Frank, S. Marc Breedlove, Stephen E. Glickman (6 December 1998). Sexual Dimorphism of Perineal Muscles and Motoneurons in Spotted Hyenas; The Journal of Comparative Neurology, Volume 375, Issue 2 , Pages 333 - 343. Retrieved 11 September 2007.
• Goudarzi, Sara (16 November 2006). Gay Animals Out of the Closet?: First-ever Museum Display Shows 51 Species Exhibiting Homosexuality. MSNBC. Retrieved on 12 September 2007.
• Harrold, Max (16 February 1999). Biological Exuberance: Animal Homosexuality and Natural Diversity. The Advocate, reprinted in Highbeam Encyclopedia. Retrieved on 10 September 2007.
• Holekamp, Kay E. (2003). Research: Spotted Hyena - Introduction and Overview. Michigan State University, Department of Zoology. Retrieved 11 September 2007.
• Imaginova (2007). LiveScience.com - Gay Animals: Alternate Lifestyles in the Wild - Japanese macaques; LiveScience. Retrieved 20 November 2007.
• Imaginova (2007b). LiveScience.com - Gay Animals: Alternate Lifestyles in the Wild - American Bison; LiveScience. Retrieved 20 November 2007.
• Imaginova (2007c). LiveScience.com - Gay Animals: Alternate Lifestyles in the Wild - Bottlenose Dolphins; LiveScience. Retrieved 20 November 2007.
• Imaginova (2007d). LiveScience.com - Gay Animals: Alternate Lifestyles in the Wild - Giraffes; LiveScience. Retrieved 20 November 2007.
• Imaginova (2007e). LiveScience.com - Gay Animals: Alternate Lifestyles in the Wild - Kob; LiveScience. Retrieved 20 November 2007.
• Imaginova (2007f). LiveScience.com - Gay Animals: Alternate Lifestyles in the Wild - Black Swan; LiveScience. Retrieved 20 November 2007.
• Imaginova (2007g). LiveScience.com - Gay Animals: Alternate Lifestyles in the Wild - Walrus; LiveScience. Retrieved 20 November 2007.
• Imaginova (2007h). LiveScience.com - Gay Animals: Alternate Lifestyles in the Wild - Gray Whale; LiveScience. Retrieved 20 November 2007.
• Imaginova (2007i). LiveScience.com - Gay Animals: Alternate Lifestyles in the Wild - Guianan-Cock-of-the-Rock; LiveScience. Retrieved 20 November 2007.
• Imaginova (2007j). LiveScience.com - Gay Animals: Alternate Lifestyles in the Wild - Bonobo Chimpanzees; LiveScience. Retrieved 20 November 2007.
• Kick, Russ (2001). You Are Being Lied to: The Disinformation Guide to Media Distortion, Historical Whitewashes and Cultural Myths. The Disinformation Company, ISBN 0966410076. Retrieved on 18 November 2007.
• LeVay, Simon Ph.D. (19 September 2007) The Science of Sex Nerve.com. Retrieved on 18 November 2007.
• Liggett, Dave, and Columbus Zoo and Aquarium staff (1997-2006). Bonobo Pan paniscus: Bonobos at the Columbus Zoo; Columbus Zoo and Aquarium. Retrieved on 23 November 2007.
• News-medical.net (23 October 2006). 1,500 Animal Species Practice Homosexuality. Retrieved on 10 September 2007.
• 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.
• Roughgarden, Joan (2004). Evolutions Rainbow: Diversity, Gender and Sexuality in Nature and People; University of California Press, Berkeley, pages p.13-183.
• 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.
• Solimeo, Luiz Sérgio (21 September 2004). The Animal Homosexuality Myth. National Association for Research & Therapy of Homosexuality (NARTH). Retrieved on 10 September 2007.
• Solimeo, Luiz Sérgio (2004). Defending A Higher Law: Why We Must Resist Same-Sex "Marriage" and the Homosexual Movement. Spring Grove, Pennsylvania: The American TFP, ISBN 187790533X. Retrieved on 10 September 2007.
• Sommer, Volker & Paul L. Vasey (2006). Homosexual Behaviour in Animals, An Evolutionary Perspective. Cambridge University Press, Cambridge; ISBN-10: 0521864461.
• Srivastav, Suvira (15 December-31 December 2001). Lion, Without Lioness Terragreen, News to Save the Earth. Retrieved on 2 September 2007.
• Stein, Edward (1999) The Mismeasure of Desire: The Science, Theory, and Ethics of Sexual Orientation; Oxford University Press, US; ISBN 0195142446.
• Tatarnic, Nikolai J., Gerasimos Cassis, Dieter F. Hochuli; 22 March 2006 Biology Letters Journal: Traumatic insemination in the plant bug genus Coridromius Signoret (Heteroptera: Miridae) Royal Society Publishing; Volume 2, Number 1, pg 58-61. Retrieved 12 November 2007.
• Terry, Jennifer (2000) "Unnatural Acts" In Nature: The Scientific Fascination with Queer Animals; GLQ: A Journal of Lesbian and Gay Studies (6(2):151-193; OI:10.1215/10642684-6-2-151); Duke University Press.
• Utzeri, C. & C. Belfiore (1990): Anomalous tandems in Odonata. Fragmenta Entomologica 22(2), pp. 271-288. Retrieved 11 September 2007.
• Vasey, Paul L. (1995), Homosexual Behaviour in Primates: A Review of Evidence and Theory; International Journal of Primatology 16: p 173-204.
• Wilson, Sexing the Hyena: "The males mount each other" University of Chicago Press. Retrieved 11 September 2007.
• Zimmer, Carl (2000); Parasite Rex: Inside the Bizarre World of Nature's Most Dangerous Creatures; Simon and Schuster, ISBN 0743213718. Retrieved 18 November 2007.

[edit] References

1. ^ Smith (February 7, 2004)
2. ^ Bagemihl (1999)
3. ^ ^{a b c} News-medical.net (2006)
4. ^ Bagemihl (1999) page 213
5. ^ Bagemihl (1999)
6. ^ Harrold (1999)
7. ^ Solimeo (2004)
8. ^ Solimeo (2004b)
9. ^ Bagemihl (1999) pages 122-166
10. ^ Roughgarden (2004) pp.13-183
11. ^ Vasey (1995) pages 173-204
12. ^ Sommer & Vasey (2006)
13. ^ LeVay, (19 September 2007)
14. ^ Dunkle (1991)
15. ^ Utzeri (1990)
16. ^ Bagemihl (1999) page 427
17. ^ Bagemihl (1999) page 441
18. ^ Bagemihl (1999) page 469
19. ^ Bagemihl (1999) page 405
20. ^ Bagemihl (1999) pages 388,389
21. ^ Bagemihl (1999) pages 81, 88
22. ^ Bagemihl (1999) page 432
23. ^ Bagemihl (1999) page 339
24. ^ Bagemihl (1999) page 334
25. ^ Bagemihl (1999) page 448
26. ^ Bagemihl (1999) pages 310, 314
27. ^ Bagemihl (1999) page 413
28. ^ Bagemihl (1999), pages 109, 469
29. ^ Bagemihl (1999) pages 83
30. ^ Bagemihl (1999) pages 544-8
31. ^ Bagemihl (1999) page 621-6
32. ^ 365 Gay.com (2005)
33. ^ ^{a b} Bagemihl (1999), page 665
34. ^ Bagemihl (1999), page 37
35. ^ Bagemihl (1999), pages 658, 664
36. ^ Bagemihl (1999), pages 658, 664
37. ^ Bagemihl (1999), page 665
38. ^ Bagemihl (1999), page 658
39. ^ Bagemihl (1999), page 658
40. ^ Bagemihl (1999), page 664
41. ^ Bagemihl (1999), page 665
42. ^ Bagemihl (1999), pages 658, 665
43. ^ Bagemihl (1999), page 658
44. ^ Bagemihl (1999), pages 658, 664
45. ^ Bagemihl (1999), pages 232, 233, 244
46. ^ Bagemihl (1999), page 658
47. ^ ^{a b} Bagemihl (1999), page 658
48. ^ ^{a b c d e} Bagemihl (1999), page 657
49. ^ ^{a b c d e f g h i j k} Bagemihl (1999), page 657, 658
50. ^ ^{a b c} Bagemihl (1999), page 658
51. ^ Bagemihl (1999), page 658
52. ^ Bagemihl (1999), pages 232, 664
53. ^ Bagemihl (1999), pages 658, 664
54. ^ ^{a b} Bagemihl (1999), pages 663–664
55. ^ Bagemihl (1999), page 658
56. ^ Bagemihl (1999), page 658
57. ^ Bagemihl (1999), page 658
58. ^ Bagemihl (1999), page 658
59. ^ Bagemihl (1999), page 657
60. ^ ^{a b} Bagemihl (1999), pages 657, 658
61. ^ Bagemihl (1999), pages 243, 664
62. ^ Bagemihl (1999), page 657
63. ^ Bagemihl (1999), pages 668, 667
64. ^ Bagemihl (1999), page 666
65. ^ ^{a b c} Bagemihl (1999), page 666
66. ^ Bagemihl (1999), page 666
67. ^ Tatarnic1 et al., 22 March 2006
68. ^ Bagemihl (1999) page 660
69. ^ Bagemihl (1999) page 667
70. ^ Zimmer (2000)
71. ^ Bagemihl (1999) page 667
72. ^ ^{a b} Bagemihl (1999) page 657
73. ^ ^{a b c} Bagemihl (1999) pages 704, 713
74. ^ ^{a b c d e} Bagemihl (1999) pages 150, 232, 236, 246
75. ^ ^{a b c} Bagemihl (1999) pages 33–34, 196, 217, 219, 232
76. ^ Bagemihl (1999) page 668
77. ^ Bagemihl (1999) page 666
78. ^ Bagemihl (1999) page 595
79. ^ ^{a b} Bagemihl (1999) pages 9, 649, 665
80. ^ ^{a b} Bagemihl (1999) page 666
81. ^ Bagemihl (1999) page 658
82. ^ ^{a b} Out magazine, By The Numbers sourced to the Journal of Evolutionary Biology; February 2009. Accessed 2009-01-17.
83. ^ ^{a b} Bagemihl (1999) page 3
84. ^ ^{a b c d} Bagemihl (1999) page 232
85. ^ Bagemihl (1999) pages 666, 660
86. ^ ^{a b c} Bagemihl (1999) pages 236, 704, 713
87. ^ Bagemihl (1999) pages 666, 660
88. ^ Bagemihl (1999) pages 661–2
89. ^ Bagemihl (1999) page 661
90. ^ Bagemihl (1999) page 660
91. ^ Bagemihl (1999) page 660
92. ^ ^{a b c d e f g h i j k l m n} Bagemihl (1999), pages 661–2
93. ^ Bagemihl (1999) page 660
94. ^ Bagemihl (1999), page 660
95. ^ Bagemihl (1999), page 659
96. ^ Bagemihl (1999), page 660
97. ^ Bagemihl (1999), page 660
98. ^ Bagemihl (1999), page 661
99. ^ Bagemihl (1999), page 660
100. ^ Bagemihl (1999), page 660
101. ^ Bagemihl (1999), page 660
102. ^ Bagemihl (1999), page 660