Homosexuality in animals 547826 226114157 2008-07-16T21:48:30Z User0529 7280847 refs to below see also (wp:layout) [[Image:Bonobo 011.jpg|thumb|The [[Bonobo]] displays the highest rate of homosexual activity in any animal, being a fully [[bisexual]] species.<ref name=penisfencing>{{cite book | author= Frans B. M. de Waal |authorlink= Frans de Waal| title=The ape and the sushi master : cultural reflections by a primatologist | year 2001 | publisher=Basic Books | chapter=Bonobos and Fig Leaves}}</ref><ref>[http://www.colszoo.org/animalareas/aforest/bonobo.html Bonobos at the Columbus Zoo]</ref>]] '''[[Homosexual]]''', as well as [[bisexual]], behavior is widespread in the '''[[animal kingdom]]'''. [[Non-human animal sexual behavior|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 as most species have yet to be studied.<ref name="‘Catalogue of Life’ reaches">{{cite web | last =Gordon | first =Dr Dennis | authorlink = | coauthors = | title=‘Catalogue of Life’ reaches one million species | publisher=[[National Institute of Water and Atmospheric Research]] | date=[[10 April]] [[2007]] | url =http://www.niwascience.co.nz/pubs/mr/archive/2007-04-10-3 | accessdate = 2007-09-10}}</ref> A 1999 review by researcher [[Bruce Bagemihl]] shows that homosexual behavior, not necessarily [[sex]], has been observed in close to 1500 species, ranging from [[primates]] to [[Acanthocephala|gut worms]], and is well documented for 500 of them.<ref>Bruce Bagemihl, ''Biological Exuberance: Animal Homosexuality and Natural Diversity,'' St. Martin's Press, 1999; ISBN 0312192398</ref><ref name="Biological Exuberance: Animal">{{cite web | last =Harrold | first =Max | title=Biological Exuberance: Animal Homosexuality and Natural Diversity | publisher=[[The Advocate]], reprinted in Highbeam Encyclopedia | date=1999-02-16 | url =http://www.encyclopedia.com/doc/1G1-53877996.html | accessdate = 2007-09-10}}</ref> Homosexuality in animals is seen as controversial because some assert it points to the naturalness of [[Human sexuality|homosexuality in humans]], while others counter that it has no logical or ethical implications and is nonsensical to use animal behavior to justify what is or is not [[Morality|immoral]] (see ''[[appeal to nature]]'').<ref name="The Animal Homosexuality Myth">{{cite web | last =Solimeo | first =Luiz Sérgio | authorlink = | coauthors = | title=The Animal Homosexuality Myth | publisher=[[NARTH]], National Association for Research & Therapy of Homosexuality | date=[[21 September]] [[2004]] | url =http://www.narth.com/docs/animalmyth.html | accessdate = 2007-09-10}}</ref><ref name="Defending A Higher Law">{{cite web | last =Solimeo | first =Luiz Sérgio | authorlink = | coauthors = | title=Defending A Higher Law: Why We Must Resist Same-Sex "Marriage" and the Homosexual Movement | publisher=Spring Grove, Penn.: The American TFP | date=2004, ISBN 187790533X | url =http://www.narth.com/docs/animalmyth.html | accessdate = 2007-09-10}}</ref> {{Sexual orientation}} ==Applying the term "homosexual" to animals== The term ''[[homosexual]]'' was coined in [[Prussia]] in 1869 to describe same-sex sexual attraction and sexual behaviour in humans <ref>The first known use of the word ''Homoseksuäl'' is found in Benkert Kertbeny, K.M. (1869): Paragraph 143 des Preussichen Strafgesetzebuches vom 14/4-1851 und seine Aufrechterhaltung als Paragraph 152 im Entwurf eines Strafgesetzbuches fur den Norddeutschen Bundes, Leipzig, 1869. Reprinted in ''Jahrbuch fur sexuelle Zwischenstufen 7'' (1905), pp. 1-66</ref>. Its use in animal studies has been controversial for two main reasons: animal sexuality and motivating factors have been and remain poorly understood, and the term has strong cultural implications in western society that are irrelevant for other species than [[human]]s.<ref name="Rethinking Sex">{{cite web | last =Dorit | first =Robert | title= Rethinking Sex | publisher=[[American Scientist]] | date=September-October 2004 | url =http://www.americanscientist.org/template/BookReviewTypeDetail/assetid/35487 | accessdate = 2007-09-11}}</ref>. Thus homosexual behaviour has been given a number of terms over the years. The term "homosexual" is preferred over "gay", "lesbian" and other terms currently in uses, as these are seen as even more bound to the human condition<ref>Bruce Bagemihl, Biological Exuberance: Animal Homosexuality and Natural Diversity, St. Martin's Press, 1999; pp.122-166</ref>. Animal preference and motivation is always inferred from behaviour. In wild animals, researchers will as a rule not be able to map the entire life of an individual, and must interfere from frequency of single observations of behaviour. The correct usage of the term ''homosexual'' is that an animal ''exhibits homosexual behaviour'', however this article conforms to the usage by modern research <ref>Bruce Bagemihl, Biological Exuberance: Animal Homosexuality and Natural Diversity, St. Martin's Press, 1999; pp.122-166</ref><ref>[[Joan Roughgarden]], Evolutions rainbow: Diversity, gender and sexuality in nature and people, [[University of California Press]], Berkeley, 2004; pp.13-183</ref><ref>Vasey, Paul L. (1995), Homosexual behaviour in primates: A review of evidence and theory, [[International Journal of Primatology]] 16: p 173-204</ref><ref>Sommer, Volker & Paul L. Vasey (2006), Homosexual Behaviour in Animals, An Evolutionary Perspective. [[Cambridge University Press]], Cambridge. ISBN-10: 0521864461</ref> applying the term ''homosexuality'' to all sexual behaviour ([[copulation]], [[genitals|genital]] stimulation, mating games and sexual [[Display (zoology)|display behaviour]]) between animals of the same sex. In most instances, it is presumed that the homosexual behaviour is but part of the animals overall sexual behavioural repertoire, making the animal "bisexual" rather than "homosexual" as the terms are commonly understood in humans<ref>Sommer, Volker & Paul L. Vasey (2006), Homosexual Behaviour in Animals, An Evolutionary Perspective. [[Cambridge University Press]], Cambridge. ISBN-10: 0521864461</ref>, but cases of clear homosexual preference and exclusive homosexual pairs are known (see examples for details). ==Research on homosexual behavior in animals== The presence of [[same-sex sexual behavior]] was not 'officially' observed on a large scale until recent times, possibly due to [[Observer effect|observer bias]] caused by social attitudes to [[same-sex sexual behavior]].<ref>[[Joan Roughgarden]], Evolutions rainbow: Diversity, gender and sexuality in nature and people, [[University of California Press]], Berkeley, 2004</ref> Georgetown University [[biologist]] Janet Mann states "Scientists who study the topic are often accused of trying to forward an agenda, and their work can come under greater scrutiny than that of their colleagues who study other topics.<ref name="Homosexuality Commo">{{cite web | last = Moskowitz | first =Clara | title=Homosexuality Common in the Wild, Scientists Say | publisher=Fox News | date=[[19 May]] [[2008]] | url =http://www.foxnews.com/story/0,2933,356639,00.html | accessdate = 2008-07-02}}</ref> They also noted "Not every sexual act has a reproductive function ... that's true of humans and non-humans."<ref name="Homosexuality Commo"/> It appears to be widespread amongst social [[bird]]s and [[mammal]]s, particularly the sea mammals and the [[primates]]. The true extent of homosexuality in animals is not known. While studies have demonstrated homosexual behaviour in a number of species, [[Petter Bøckman]], the scientific advisor of the exhibition [[Against Nature?]] speculate that the true extent of the phenomenon may be much larger than currently recognized: {{quote|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 urchin]]s and [[aphis]]. Moreover, a part of the animal kingdom is [[hermaphrodite|hermaphroditic]], truly bisexual. For them, homosexuality is not an issue.<ref name="1,500 Animal Species Practice">{{cite web | url = http://www.news-medical.net/?id=20718 | title = 1,500 Animal Species Practice Homosexuality | date = [[2006-10-23]] | publisher = News-medical.net | accessdate = 2007-09-10}}</ref>}} Some researchers believe it to have its origin in male social organization and social dominance, similar to the dominance traits shown in [[prison sexuality]]. Others, particularly [[Joan Roughgarden]], [[Bruce Bagemihl]], Thierry Lodé<ref>[[Thierry Lodé]] "La guerre des sexes chez les animaux" Eds O Jacb, Paris, 2006, ISBN 2-7381-1901-8 </ref> and [[Paul Vasey]] suggest the social function of sex (both homosexual and heterosexual) is not necessarily connected to dominance, but serves to strengthen alliances and social ties within a flock. Others have argued that social organization theory is inadequate because it cannot account for some homosexual behaviors, for example, [[penguin]] species where same-sex individuals mate for life and refuse to pair with females when given the chance.<ref name="Gay Penguins Resist">{{cite web | title=Gay Penguins Resist 'Aversion Therapy' | publisher=365 Gay.com | date=[[February 11]] [[2005]] | url =http://www.365gay.com/newscon05/02/021105penguins.htm | accessdate = 2007-09-10}}</ref> While reports on many such mating scenarios are still only anecdotal, a growing body of scientific work confirms that permanent homosexuality occurs in species with permanent pair bonds, but also in non-monogamous species like sheep. One report on sheep cited below states: {{quote|Approximately 8% of rams exhibit sexual preferences [that is, even when given a choice] for male partners (male-oriented rams) in contrast to most rams, which prefer female partners (female-oriented rams). We identified a cell group within the medial preoptic area/anterior hypothalamus of age-matched adult sheep that was significantly larger in adult rams than in ewes...<ref name="The Volume of a Sexually Dimorphic">{{cite web | last =Roselli | first =Charles E. | authorlink = | coauthors =Kay Larkin, John A. Resko, John N. Stellflug and Fred Stormshak | title=The Volume of a Sexually Dimorphic Nucleus in the Ovine Medial Preoptic Area/Anterior Hypothalamus Varies with Sexual Partner Preference | publisher=Journal of [[Endocrinology]], Endocrine Society, Bethesda, MD, | date=2004, vol. 145, no2, pp. 478-483 | url =http://cat.inist.fr/?aModele=afficheN&cpsidt=15419685 | accessdate = 2007-09-10}}</ref>}} In fact, apparent homosexual individuals are known from all of the traditional domestic species. ==Cross species sex== {{Main|Animal sexual behaviour#Cross species sex}} Although a commonly held conception is that animals' sexuality is instinctive almost to the point of being mechanistic, research regularly records that many animals are sexual opportunists, and may show an interest in other partners than their own or related species.<ref>http://news.bbc.co.uk/2/hi/science/nature/7379554.stm "The seal then alternated between resting on the penguin, and thrusting its pelvis, trying to insert itself, unsuccessfully."</ref> This is more visible in domesticated species, as domestication commonly selects for increased breeding rate (and so an accelerated breeding cycle has commonly arisen in domesticated species over the centuries), and also because these species are easier to witness by humans. Cross-species sex has been observed in the wild and investigations describe productive and non-productive inter-species mating as a "natural occurrence".<ref>Haeberle (1978) states that sexual intercourse is not so very unusual between animals of different species as it is between humans and animals. Kinsey et al. (1948, p. 668) states "When one examines the observed cases of such crosses, and especially the rather considerable number of instances in which primates, including man, have been involved, one begins to suspect that the rules about intraspecific mating are not so universal as tradition would have it". Kinsey et al. (1953) further point out that genetic studies have shown the existence of a "large number" of inter-specific hybrids, that have occurred in the wild, and investigations (eg, Cauldwell, 1968; Ford & Beach, 1951; Harris, 1969; Masters, 1962; Ullerstam, 1966, etc) have found that interspecies mating is a "natural occurrence".' (Cited by [[Hani Miletski|Miletski]], in her [[anthrozoology|anthrozoological]] study of animal-human sexuality, 1999, p.51)</ref><ref>LODÉ T., GUIRAL G. & PELTIER D. 2005. European mink-polecat hybridization events: hazards from natural process ? Journal of Heredity 96 (2): 1-8 </ref> Most observations, however, are from animals in captivity including zoos. If the pair are a male and a female, [[Hybrid (biology)|hybrid]] offspring can result if the two species are related. However, this offspring may not be able to breed itself. The [[mule]], for example (horse/donkey cross) is normally sterile, whilst the [[liger]] (lion/tiger cross) is sometimes fertile. Novosibirsk zoo director Rostislav Shilo says on the liger (born in his zoo); “It’s just that the lion and the tiger live in neighboring caves in the Novosibirsk zoo, and got used to each other. It’s practically impossible in the wild.”. Cross species sex in the wild has been observed between several species, among them [[blue tit]] and [[great tit]], [[Chimpanzee]]s and [[olive baboon]]s and [[Boto|Amazon River Dolphin]] and the [[tucuxi]] dolphin. ==Some selected species and groups== {{see also|List of animals displaying homosexual behavior}} ===American Bison=== [[Image:American bison k5680-1.jpg|thumb|The American Bison is a [[bovine]] [[mammal]] which commonly displays homosexual behavior.]] Courtship, mounting, and full [[anal sex|anal penetration]] between bulls has been noted to occur among [[American Bison]]. The [[Mandan]] nation Okipa festival concludes with a ceremonial enactment of this behaviour, to "ensure the return of the buffalo in the coming season."<ref name="Left-Handed Bears & Androgynous">{{cite web | last =Bagemihl | first =Bruce | title= Left-Handed Bears & Androgynous Cassowaries: Homosexual/transgendered animals and indigenous knowledge | publisher=[[Whole Earth Magazine]] | date=Spring 2000 | url =http://www.wholeearthmag.com/ArticleBin/338.html | accessdate = 2007-06-16}}</ref> Also, mounting of one female by another is common among [[cattle]]. Inter-sexual bison also occur. The [[Lakota people|Lakota]] refer to them as ''pte winkte'' —''pte'' meaning bison and ''winkte'' designating [[two-spirit]]— thereby drawing an explicit parallel between [[transgender]] in animals and people.<ref name="Left-Handed Bears & Androgynous"/> ===Birds=== ====Black swans==== [[Image:Black Swans.jpg|left|thumb|The [[Black Swan]], ''Cygnus atratus'' is a large [[Wildfowl|waterbird]] which breeds mainly in the southeast and southwest regions of [[Australia]].]] An estimated one-quarter of all [[black swans]] pairings are homosexual and they steal nests, or form temporary threesomes with females to obtain eggs, driving away the female after she lays the eggs.<ref name="Gay animals out of the closet?">{{cite web | last =Goudarzi | first =Sara | title=Gay animals out of the closet?: First-ever museum display shows 51 species exhibiting homosexuality | publisher=[[MSNBC]] | date=[[16 November]] [[2006]] | url=http://www.msnbc.msn.com/id/15750604/ | accessdate = 2007-09-12}}</ref> More of their cygnets survive to adulthood than those of different-sex pairs possibly due to their superior ability to defend large portions of land. ====Gulls==== Studies have shown that 10 to 15 percent of female western gulls in some populations in the wild are [[lesbian]].<ref name="Central Park Zoo's gay penguins">{{cite web | last =Smith | first =Dinitia | authorlink = | coauthors = | title=Central Park Zoo's gay penguins ignite debate | publisher=[[San Francisco Chronicle]], reprinted from New York Times | date=[[February 7]] [[2004]] | url =http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2004/02/07/MNG3N4RAV41.DTL | accessdate = 2007-09-10}}</ref> ====Mallards==== [[Image:Males Anas platyrhynchos 2 .jpg|thumb|Two male [[Mallard]]s,''Anas platyrhynchos'']] Mallards form male-female pairs only until the female lays eggs, at which time she is left by the male. The clutch is 8–13 eggs, which are incubated for 27–28 days to hatching with 50–60 days to fledging. The ducklings are [[precocial]], and can swim and feed themselves on insects as soon as they hatch, although they stay near the female for protection. Young ducklings are not naturally waterproof and rely on the mother to provide waterproofing. Mallards also have rates of male-male sexual activity that are unusually high for birds.<ref name="mallard"/> In some cases, as many as 19% of pairs in a Mallard population are male-male homosexual<ref name="mallard">Bruce Bagemihl, Biological Exuberance: Animal Homosexuality and Natural Diversity, St. Martin's Press, 1999; ISBN 0312192398</ref> ====Penguins==== In early February 2004 the ''[[New York Times]]'' reported a male pair of [[chinstrap penguin]]s in the [[Central Park Zoo]] in [[New York City]] were partnered and even successfully hatched a female chick from an egg.<ref name="Love That Dare Not Squeak">{{cite web | last =Smith | first =Dinitia | authorlink = | coauthors = | title=Love That Dare Not Squeak Its Name | publisher=[[New York Times]] | date=[[February 7]] [[2004]] | url =http://query.nytimes.com/gst/abstract.html?res=FA0C1EF83A5F0C748CDDAB0894DC404482 | accessdate = 2007-09-10}}</ref> Other [[penguin]]s in New York have also been<ref name="They're in love. They're gay">{{cite web | title=They're in love. They're gay. They're penguins... And they're not alone. | publisher=[[Columbia University]], Columbia News Service | date=[[June 10]] [[2002]] | url =http://www.jrn.columbia.edu/studentwork/cns/2002-06-10/591.asp | accessdate = 2006-07-21}}</ref> reported to be forming same-sex pairs. Zoos in [[Japan]] and [[Germany]] have also documented gay male penguin couples.<ref name="Gay Penguins Resist"/> The couples have been shown to build nests together and use a stone to replace an egg in the nest. Researchers at [[Rikkyo University]] in [[Tokyo]], found 20 gay pairs at 16 major aquariums and zoos in Japan. Bremerhaven Zoo in Germany attempted to break up the gay male couples by importing female penguins from [[Sweden]] and separating the male couples, but they were unsuccessful. The zoo director stated the relationships were too strong between the gay couples. ===Bonobo and other apes=== The [[bonobo]], which has a [[matriarchal]] society (unusual amongst apes), is a fully [[bisexual]] species -- both males and females engage in heterosexual and homosexual behavior, being noted for [[lesbianism]] in particular. About 60% of all sexual activity in this species is between two or more females. While the homosexual bonding system in bonobos represent the highest frequency of homosexuality known in any species, homosexuality has been reported for all [[great apes]], including [[human]]s, as well as a number of other [[primate]] species.<ref name=penisfencing>{{cite book | author= Frans B. M. de Waal |authorlink= Frans de Waal| title=The ape and the sushi master : cultural reflections by a primatologist | year 2001 | publisher=Basic Books | chapter=Bonobos and Fig Leaves}}</ref><ref>[http://www.colszoo.org/animalareas/aforest/bonobo.html Bonobos at the Columbus Zoo]</ref><ref name=ancestor>{{cite book |last=Dawkins |first=Richard |authorlink=Richard Dawkins |title=The Ancestor's Tale |year=2004 |publisher=Houghton Mifflin |chapter=Chimpanzees}}</ref><ref name=songweaver>{{cite web|url= http://songweaver.com/info/bonobos.html|title= Bonobo Sex and Society|accessdate= 2006-07-17|author= Frans B. M. de Waal|authorlink= Frans de Waal |year= 1995|month= March|work= Scientific American|pages= 82-88}}</ref><ref>Frans de Waal, "Bonobo Sex and Society" in ''Scientific American'' (March 1995), p. 82ff</ref><ref>[http://www.primates.com/bonobos/bonobosexsoc.html The behavior of a close relative challenges assumptions about male supremacy in human evolution]</ref><ref>[http://www.bio.davidson.edu/people/vecase/Behavior/Spring2004/laird/Social%20Organization.htm Courtney Laird, "Social Organization"]</ref><ref> Stanford, C. B. (1998). The social behavior of chimpanzees and bonobos. Current Anthropology 39: 399–407.</ref><ref> Kano, Takayoshi (1992). The Last Ape: Pygmy Chimpanzee Behavior and Ecology. Stanford, CA: Stanford University Press.</ref> ===Bottlenose Dolphins=== [[Bottlenose Dolphin]] males have been observed working in pairs or larger groups to follow and/or restrict the movement of a female for weeks at a time, waiting for her to become sexually receptive. The same pairs/groups have also been observed engaging in ardent sexual play with each other. Janet Mann, [[Georgetown University]] professor of biology and psychology, argues that the strong personal behaviour among male dolphin calves is about bond formation and benefits the species in an evolutionary context.<ref name="Central Park Zoo's gay penguins"/> She cites studies showing that these dolphins later in life as adults are in a sense bisexual, and the male bonds forged earlier in life work together for protection as well as locating females to reproduce with. ===Dragonflies=== [[Image:Head of dragonfly 2.jpg|thumb|The head of Darner Dragonfly (Basiaeschna janata).]] Male homosexuality has been inferred in several species of [[dragonflies]] (the [[Order (biology)|order]] [[Odonata]]). The cloacal pinchers of male damselflies and dragonflies inflict characteristic head damage to females during sex. A survey of 11 species of damsel and dragonflies<ref>Dunkle, S.W. (1991), Head damage from mating attempts in dragonflies (Odonata:Anisoptera). Entomological News 102, pp. 37-41</ref><ref>Utzeri, C. & C. Belfiore (1990): Anomalous tandems in Odonata. Fragmenta Entomologica 22(2), pp. 271-288</ref> has revealed such mating damages in 20 to 80 % of the males too, indicating a fairly high occurrence of sexual coupling between males. ===Elephants=== African, as well as Asiatic males will engage in same-sex bonding and mounting. Such encounters are often associated with affectionate interactions, such as kissing, trunk intertwining, and placing trunks in each other's mouths. The encounters are analogous to heterosexual bouts, one male often extending his trunk along the other's back and pushing forward with his tusks to signify his intention to mount. Unlike heterosexual relations, which are always of a fleeting nature, those between males result in a "companionship", consisting of an older individual and one or two younger, attendant males. Same-sex relations are common and frequent in both sexes, with Asiatic elephants in captivity devoting roughly 45% of sexual encounters to same-sex activity.<ref>Bruce Bagemihl, Biological Exuberance: Animal Homosexuality and Natural Diversity, St. Martin's Press, 1999; pp.427-430</ref> ===Fruit flies=== Male ''[[Drosophila melanogaster]]'' flies bearing two copies of a mutant allele in the [[Fruitless (gene)|fruitless]] gene court and attempt to mate exclusively with other males. ===Giraffes=== [[Image:Two Giraffes.PNG|thumb|Two male [[giraffes]] in [[Kenya]].]] Researchers have treated homosexual behavior in animals as a [[taboo]] subject perhaps from innocent confusion or even from a fear of "being ridiculed by their colleagues."<ref name="1,500 Animal Species Practice"/> A case of overlooking behaviour is noted by [[Bruce Bagemihl]] describing mating giraffes where nine out of ten pairings occur between males. {{cquote|Every male that sniffed a female was reported as sex, while anal intercourse with orgasm between males was only "revolving around" [[dominance]], competition or [[greeting]]s.<ref name="1,500 Animal Species Practice"/>}} ===Japanese Macaque=== With the [[Japanese Macaque]], also known as the "snow [[monkey]]", [[Homosexuality|same-sex relations]] are frequent, though rates vary between troupes. Females will form "consortships" characterized by affectionate social and sexual activities. In some troops up to one quarter of the females will form such bonds, which will vary in duration from a few days to a few weeks. Often, strong and lasting friendships will result from such pairings. Males also have same-sex relations, typically with multiple partners of the same age. Affectionate and playful activities are associated with such relations.<ref>Bruce Bagemihl, ''Biological Exuberance: Animal Homosexuality and Natural Diversity,'' St. Martin's Press, 1999; pp.302-305</ref> ===Lions=== [[Image:Lions - melbourne zoo.jpg|left|thumb|A group of male [[lion]]s at the [[Melbourne]] zoo.]] Both male and female lions have been seen to interact [[animal sexuality|homosexually]].<ref>Bruce Bagemihl, ''Biological Exuberance: Animal Homosexuality and Natural Diversity,'' St. Martin's Press, 1999; pp.302-305. In his discussion of lion same-sex relations, Bagemihl is making use of published work by: J.B. Cooper, "An Exploratory Study on African Lions" in ''Comparative Psychology Monographs'' 17:1-48; R.L. Eaton, "The Biology and Social Behavior of Reproduction in the Lion" in Eaton, ed. ''The World's Cats,'' vol. II; pp.3-58; Seattle, 1974; G.B. Schaller, ''The Serengeti Lion''; University of Chicago Press, 1972</ref><ref> {{cite web | last =Srivastav | first =Suvira | title =Lion, Without Lioness | work =TerraGreen: News to Save the Earth | publisher = Terragreen | date = [[15 December]]-[[31 December]] [[2001]] | url =http://www.teri.res.in/teriin/terragreen/issue3/feature.htm | accessdate = 2007-09-02}}</ref> Male lions pair-bond for a number of days and initiate homosexual activity with affectionate nuzzling and caressing, leading to mounting and thrusting. About 8% of mountings have been observed to occur with other males, while female pairings are held to be fairly common in captivity but have not been observed in the wild. ===Lizards=== Whiptail lizard ([[Teiidae]] genus) females have the ability to reproduce through [[parthenogenesis]] and as such males are rare and sexual breeding non-standard. Females engage in sexual behavior to stimulate [[ovulation]], with their behavior following their hormonal cycles; during low levels of estrogen, these (female) lizards engage in "masculine" sexual roles. Those animals with currently high estrogen levels assume "feminine" sexual roles. Lizards that perform the courtship ritual have greater fertility than those kept in isolation due to an increase in hormones triggered by the sexual behaviors. So, even though asexual whiptail lizards populations lack males, sexual stimuli still increase reproductive success. From an [[Evolutionary]] standpoint, these females are passing their full genetic code to all of their offspring (rather than the 50% of genes that would be passed in sexual reproduction). Certain species of [[gecko]] also reproduce by parthenogenesis. ===Polecat=== [[Image:Ilder.jpg|thumb|European polecats (''Mustela putorius'') at ''Skandinavisk Dyrepark'', [[Djursland]], [[Denmark]].]] [[European polecat]]s ''Mustela putorius'' were found to engage homosexuality in non sibling animals. Deliberate exclusive homosexuality with mounting and anal penetration in this solitary species apparently serves no adaptive function<ref>[[Thierry Lodé]] "la guerre des sexes chez les animaux" Eds O Jacob, Paris, 2006.ISBN 2-7381-1901-8</ref>. ===Sheep=== An October 2003 study by Dr. Charles E. Roselli et al. (Oregon Health and Science University) states that homosexuality in male sheep (found in 8% of rams) is associated with a region in the rams' brains which the authors call the "ovine Sexually Dimorphic Nucleus" (oSDN) which is two times smaller than the corresponding region in heterosexual male sheep.<ref name="The Volume of a Sexually Dimorphic">{{cite web | last =Roselli | first =Charles E. | authorlink = | coauthors =Kay Larkin, John A. Resko, John N. Stellflug and Fred Stormshak | title=The Volume of a Sexually Dimorphic Nucleus in the Ovine Medial Preoptic Area/Anterior Hypothalamus Varies with Sexual Partner Preference | publisher=[[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. | date=2004, Vol. 145, No. 2 478-483 | url =http://endo.endojournals.org/cgi/content/abstract/145/2/478 | accessdate = 2007-09-10}}</ref> [[Image:St Croix sheep.jpg|thumb|left|A pair of [[St. Croix]] [[ewe]]s.]] It should be noted that some view this study to be flawed in that the determination of homosexuality within the sheep (sample population of 27 for the study) was to have animals who were unable to mount female ewes placed in a cage with two stanchioned males and two unstanchioned females (i.e. the males could not move or struggle while the females could). Given the aggressive nature of sheep copulation, the uneven treatment of males and females, many see this as simply evidence that the sheep in question were unable to be aggressive enough to mount females. The results were situational sexuality, unlike the bonds seen in human homosexuality.{{Fact|date=September 2007}} The scientists found that, "The oSDN in rams that preferred females was significantly larger and contained more [[neurons]] than in male-oriented rams and ewes. In addition, the oSDN of the female-oriented rams expressed higher levels of [[aromatase]], a substance that converts [[testosterone]] to [[estradiol]], a form of [[estrogen]] which is believed to facilitate typical male sexual behaviors. [[Aromatase]] expression was no different between male-oriented rams and ewes." "The dense cluster of neurons that comprise the oSDN express cytochrome P450 aromatase. Aromatase mRNA levels in the oSDN were significantly greater in female-oriented rams than in ewes, whereas male-oriented rams exhibited intermediate levels of expression." These results suggest that "...naturally occurring variations in sexual partner preferences may be related to differences in brain anatomy and its capacity for estrogen synthesis."<ref name="The Volume of a Sexually Dimorphic"/> As noted prior, given the potential unagressiveness of the male population in question, the differing aromatase levels may also have been evidence of aggression levels, not sexuality. It should also be noted that the results of this study have not been confirmed by other studies. ===Spotted Hyena=== [[Image:Spotted hyena2.jpg|right|thumb|The '''Spotted Hyena''' is a moderately large, terrestrial carnivore native to [[Africa]].]] The female [[Spotted Hyena]] has a unique urinary-genital system, closely resembling the penis of the male. The family structure is matriarchal and dominance relationships with strong sexual elements are routinely observed between related females. Early naturalists thought hyenas were [[hermaphrodite]]s or commonly practiced [[homosexuality]], largely due to the female [[spotted hyena#Reproduction|spotted hyena]]'s unique [[urogenital system]] which looks more like a penis than a vagina.<ref name="Like mother, like cubs">{{cite web | title= Like mother, like cubs: Hyena alpha moms jumpstart cubs with hormonal jolt | publisher=[[Michigan State University]] | date=2006 | url=http://hyenas.zoology.msu.edu/crocuta/hyena_research_overview.html | accessdate = 2007-09-11}}</ref> According to early writings such as [[Ovid]]'s ''[[Metamorphoses]]'' and the ''[[Physiologus]]'', the hyena continually changed its sex and nature from male to female and back again. In ''[[Paedagogus]]'', Clement of Alexandria noted that the hyena (along with the [[hare]]) was "quite obsessed with sexual intercourse." Many Europeans associated the hyena with sexual deformity, prostitution, deviant sexual behavior and even witchcraft. Research has shown that "in contrast to most other female mammals, female Crocuta are male-like in appearance, larger than males, and substantially more aggressive,"<ref name="Research: Spotted Hyena - Introduction">{{cite web | last =Holekamp | first =Kay E. | authorlink = | coauthors = | title=Research: Spotted Hyena - Introduction and Overview | publisher=[[Michigan State University]], Department of [[Zoology]] | date=2003 | url=http://hyenas.zoology.msu.edu/crocuta/hyena_research_overview.html | accessdate = 2007-09-11}}</ref> they have "been [[masculine|masculinized]] without being [[Femininity|defeminized]].”<ref name="Like mother, like cubs"/> This unique genitalia and aggressive behavior in the female hyena has led to the understanding that more aggressive females are better able to compete for resources including food and mating partners.<ref name="Top Dogs: Steroid hormones">{{cite web | last =Selim | first =Jocelyn | title=Top Dogs: Steroid hormones give hyenas a head start. | publisher=[[Discover Magazine]] | date=2006-04-28 | url=http://discovermagazine.com/2006/apr/hormone-hyenas | accessdate = 2007-09-11}}</ref><ref name="Like mother, like cubs"/> Research has shown that "elevated levels of [[testosterone]] [[in utero]]"<ref name="Sexual Dimorphism of Perineal"/> contributes to extra aggressiveness from their mother and both males and females mount members of the same sex,<ref name="Wilson, Sexing the Hyena">{{cite web | title=Wilson, Sexing the Hyena - "The males mount each other" | publisher=[[University of Chicago Press]] | date= | url=http://www.journals.uchicago.edu/cgi-bin/resolve?SIGNS032803 | accessdate = 2007-09-11}}</ref><ref name="Sexual Dimorphism of Perineal">{{cite web | last =Forger | first =Nancy G. | coauthors =Laurence G. Frank, S. Marc Breedlove, Stephen E. Glickman | title=Sexual Dimorphism of Perineal Muscles and Motoneurons in Spotted Hyenas | publisher=The Journal of Comparative Neurology | date=[[6 December]] [[1998]], Volume 375, Issue 2 , Pages 333 - 343 | url=http://doi.wiley.com/10.1002/(SICI)1096-9861(19961111)375:2%3C333::AID-CNE11%3E3.0.CO;2-W | accessdate = 2007-09-11}}</ref> who in turn are possibly acting more [[submissive]] because of lower levels of testosterone from their mothers.<ref name="Research: Spotted Hyena - Introduction">{{cite web | last =Holekamp | first =Kay E. | authorlink = | coauthors = | title=Research: Spotted Hyena - Introduction and Overview | publisher=[[Michigan State University]], Department of [[Zoology]] | date=2003 | url =http://hyenas.zoology.msu.edu/crocuta/hyena_research_overview.html | accessdate = 2007-09-11}}</ref> ==See also== * [[Xq28]] * [[Against Nature?]] * [[Biology and sexual orientation]] * [[Freemartin]] * [[Homosexuality and psychology]] * [[Innate bisexuality]] * [[National Association for Research & Therapy of Homosexuality]] * [[Non-Human Animal Sexuality]] * [[Non-human primate experiments]] * [[Norms of reaction]] * [[Sexual orientation]] * [[Sexual orientation and medicine]] ==References== {{reflist|2}} ==External links== * [http://www.salon.com/it/feature/1999/03/cov_15featurea.html biologists' view] * [http://news.nationalgeographic.com/news/2004/07/0722_040722_gayanimal.html National Geographic] * [http://af.czu.cz/~bartos/publications/pdf/Bartos_Holeckova_2006.pdf Behaviour in Animals An Evolutionary Perspective] [[Category:Sexual orientation and science]] [[es:Homosexualidad en animales]] [[it:omosessualità negli animali]] [[he:הומוסקסואליות בבעלי חיים]] [[ja:動物の同性愛]] [[pl:Homoseksualne zachowania u zwierząt]] [[pt:Homossexualidade no reino animal]]