The Natural "Crime Against Nature"

A Brief Survey of Homosexual Behaviors In Animals

An essay in hypertext by Scott Bidstrup

"The universe is not only queerer than we suppose, but queerer than we can suppose."
--J.B.S. Haldane, evolutionary biologist

The "Crime Against Nature"

Sodomy has been stigmatized for century upon century, and in many cultures across the world and through time, mostly seeking to stigmatize relationships between members of the same sex. Almost invariably, when it is criminalized, those who criminalize it (or would do so) refer to it as the "crime against nature" or the "sin against nature." The presumption is that homosexual behavior is a perversion, and a uniquely human perversion, engaged in as the result of what is presumed to be a learned attraction to members of the same sex.

There's only one problem with that assumption: None of it is true.

J.B.S. Haldane may not have had homosexuality in mind when he uttered his famous quote about a queer universe, but it has proven to be far more prescient than he could ever have imagined. In the approximately 1,000 to 3,000 species whose behavior has been well researched and described in the literature, approximately 450 have been shown to have clear homosexual behaviors. As we'll learn in this essay, homosexuality is not at all exclusively a western, European cultural pattern as some Christian and Muslim fundamentalists and Afrocentrists (and even some African politicians) have long maintained. It's not even unique to humans. And any homosexual behavior you care to name - anal sex, same sex kissing, long-term pair bonding between members of the same sex, courtship rituals unique to homosexual couples, all these and many more are all commonly found in the animal kingdom.

The Depth and Breadth of Human and Animal Homosexuality

Homosexuality, for the purposes of this essay, can be defined as pair bonding and sex occuring between two or more members of the same sex in the same species.

The depth and breadth of human homosexual experience is far more broad than most heterosexuals realize. Far more than just a quick romp in bed, homosexuality often, even usually, involves pair bonding as deep and as long-lasting as between members of heterosexual couples. Homosexual couples have been surveyed to determine just how pair-bonding compares to heterosexual couples, and it has been found that they tend to bond between pairs (though bonded groups of more than two are not unknown), and those bonds tend to compare to those of heterosexual couples for longevity and depth of bonding. How often does this occur? The figures vary depending on how the question is asked, but homosexuality runs between 3.5% and 10.1% of the population. These numbers are surpisingly consistent across cultures and across time. The percentage of gays who form pair bonds? While I haven't seen numbers, the number has to be quite high. Among my gay acquaintences, most are in long term relationships, and only a couple of them are single. Most of those that are single have recently left relationships and are actively looking for partners. Judging from the content of the personals column, this has to be the norm.

This is not to say that all gays are tending to pair-bond. Some elect to have promiscuous, anonymous sex and don't want to be involved in relationships. Yet it's been my experience that this is usually the case with younger gay men, and often reflects a lack of emotional maturity. By the time such men are about thirty years of age, they begin to long for the emotional involvement and commitment that long term relationships offer. And they then look to settle into such relationships.

In terms of breadth of experience, it runs the gamut from mutual masturbation to anal and oral sex, petting, kissing and caressing, and such sex frequently involving fetishes.

Homosexual behavior across the animal kingdom runs the gamut too. We don't know if there are any fetishes involved, since we can't ask, and most animals don't make tools, but we do know that every other sexual behavior engaged in by human homosexuals has been observed in homosexual animals, right up to and including the fabrication and use of sexual appliances. Among dolphins, use of the blowhole as a receptive orofice has even been observed!

Same-Sex Pair Bonding in Animals

Just as in humans, animals often form long-term same-sex relationships. In species in which this normally occurs in heterosexual couples, that shouldn't come as a great surprise, but it does come as a surprise in species where heterosexual pair-bonds don't normally form for long if at all. This is true of bottlenose dolphins, which are not known to form heterosexual pair bonds, but which do in fact form homosexual pair bonds, including sex, and often lasting for life.

In animals in which "bachelor groups" form, such as bison, gazelles, antelope, sage grouse and Guinean cocks-of-the-rock, it is not uncommon for same sex pair bonds to form and last until one or the other member of the pair departs the relationship and breeds. It is also not uncommon for homosexual preference to form among members of such bachelor groups; when offered the opportunity to breed unencumbered with members of the opposite sex or the same sex, they choose the same sex.

The human pattern of bisexuality also appears in animals. In some cases, animals prefer same sex at one point in their lives, and change preference later. They may even change back and forth. In some cases, animals may seek sex with partners of either sex at random.

In animals with a seasonal breeding pattern, homosexuality can even be seasonal. Male walruses, for example, often form homosexual pair bonds and have sex with each other outside of the breeding season, but will revert to a heterosexual pattern during the normal breeding season.

Not At All Unusual

Lest you are tempted to believe that all of this is highly unusual and well out of the ordinary, you're in for quite a surprise. Homosexual behavior is not only common, but even more common in other species than in humans. While numbers are hard to come by, there are a few that present some interesting patterns. In ostriches, male homosexuality is much more common than bisexuality, but among mule deer, bisexuality is more common than homosexuality. Among our closest living relatives, the bonobo chimpanzees, few if any are either exclusively heterosexual or homosexual. Indeed, all that have been observed are exclusively permanently bisexual.

As for numbers, here are a few:

species percent homosexual percent bisexual percent heterosexual
silver gulls (females) 10 11 79
black headed gulls (both sexes) 22 15 63
Japanese macaques (both sexes) 9 56 35
bonobo chimpanzees (both sexes) 0 100 0
galahs (both sexes) 44 11 44
source: Bruce Bahemihl, Ph.D., Biological Exhuberance: Animal Homosexuality and Natural Diversity, St. Martin's Press, 2000, page 35

The occurence of homosexuality doesn't seem to be correlated with the predominance of a sex within a species. Some species show skewed sex ratios, but among them, homosexuality is not more common than in other species. For example, giant cowbirds and redwing blackbirds show male to female ratios as high as four to one, and in boat-tailed grackles and sparrow hawks, females predominate, but homosexuality has not been demonstrated in either species. Why is a mystery.

Homosexuality in the animal kingdom is an undeniable fact. It is as natural as can be. Since it is so common, it is therefore logical for the opponents of gay rights to try to explain it away.

Trying To Explain Away Animal Homosexuality

"Pseudo-heterosexuality." This is the favorite explanation of gay rights opponents. They claim that homosexuality in animals is the result of a shortage of, or unavailability of, heterosexual mates. There are a number of problems with this hypothesis.

First, in many species with skewed sex ratios, homosexuality is often seen more frequently in the sex which is in shorter supply rather than in the sex with a surplus of individuals.

Second, in some species where homosexual bonds form in a surplus sex, the other sex does not form homosexual bonds when it is in surplus. Humboldt penguins are an example. Males form homosexual bonds when there is a surplus of males, but females do not do so when they are in surplus.

Third, in other species, homosexual mountings occur with the same frequency regardless of whether there is a surplus, and sometimes even more frequently among balanced populations than skewed ones. Indeed, among yellow baboons, between 17% and 24% of younger individuals engage in same-sex mountings, when their sexes are roughly equal in their population, but among older yellow baboons, the males eventually outnumber the females by two-to-one, but homosexual mountings occur in only about 10% of such older individuals.

The "deprived of heterosexuality" argument. A variation on the pseudo-heterosexuality argument, this argument postulates that lower ranked males are deprived of the opportunity to mate and therefore turn to other males for sexual satisfaction.

The problem with this argument is that in many species in which harem-guarding occurs, there is no difference between higher ranking males and lower ranking ones as to the frequency of their homosexual mountings. This has been demonstrated in musk oxen, American bison, and New Zealand sea lions among others.

Among female homosexual pairs of Japanese macaques and Hanuman langurs engaging in homosexual behaviors, males approaching the pair may be threatened or even attacked.

When homosexual bonding does occur in the absence of opposite sex pairs, members of such a pair often resist attempts to 'convert' them back into heterosexual relationships. Even when deprived of their bonded partner, white-fronted Amazon parrots will not revert, and long-eared hedgehogs have refused heterosexual partners for as long as two and a half years, much of their natural lifetime. In the case of Stellar's sea eagles and female barn owls, both housed without opposite sexed members of their species, homosexual pair bonds among females were strong enough that when inseminated, they coparented the chicks that resulted.

Homosexual bonds can be tight. Among male rhesus macaques, crab-eating macaques, bottlenosed dolphins, cheetahs and black-headed gulls with homosexual bonded partners, the members of the pair exhibited considerable distress at being separated from their partners. In all cases, the individuals ignored opposite sex partners offered them, and showed considerable joy and exhuberance at the reintroduction of their partners.

The "Mistaken Identity" hypothesis. This one seeks to explain animal homosexuality by claiming that the same sex partner is 'confused' and unable to identify a member of the opposite sex.

The problem here is that in some animals, the difference between sexes are obvious. Vastly different body color, shape or size are an obvious clue, yet in these species, homosexual bonds still form, even when body shape precludes easy homosexual mounting.

Another problem with this hypothesis is the fact that homosexual couples often engage in very different courtship rituals than do heterosexual couples. If it were a case of mistaken identity, how would this happen? In the case of bisexual animals, it has been seen that one set of courtship rituals are used by the same individual when courting homosexual versus heterosexual partners. This would not happen if the problem were a case of mistaken identity.

The "Gross Abnormalities of Behavior" hypothesis. The assumption here is that the behavior is a manifestation of a disease process.

Scientists looking into this hypothesis often examine animals for genital abnormalities, on the assumption that there is some kind of hormonal imbalance. The fact is that they rarely ever find abnormalities, never with enough frequency for it to be statistically meaningful. That's because of the mistaken assumption by some scientists that homosexuality is some sort of hermaphroditic condition. It's not, and that's why they never find what they're looking for.

If homosexuality were a manifestation of a disease process, why is homosexuality observed in roughly the same degree in captive populations versus wild populations, or in diverse wild populations? Whatever would be causing the disease cannot be equally present in all cases, both in the field and in the wild, so differences in occurrence should show up. But they rarely do. Why?

The "population control" hypothesis. The problem with this one is that field observations directly counter it. It has been observed in ochre-bellied flycatchers and ruffed grouse populations among others, that even when opposite sex partners, territories and breeding grounds are all available, some individuals still form homosexual bonds, and the ratio by which they do rarely differs even when the population is under stress.

Something's Not Quite Right At The Zoo

Critics of this research like to point out that if homosexuality actually existed in animals, it would have been observed in zoos. Well, it has been, and for as long as zoos have been kept.

Zoo keepers who have observed this behavior historically ascribed it to the presence of stressors that exist in zoos that are not present in the wild. That was always the assumption. Such factors as same-sex isolation. Lack of stimulating activities. Unnatural living quarters. Unnatural diet. Then when field reports of similar behaviors started coming in, the existence of homosexuality in animals became to great to ignore. Today, animal behaviorists are unanimous in accepting the fact of animal homosexuality.


There's clearly a wide range of homosexual behaviors in the animal kingdom. It's widespread, common and impossible to deny or explain away any longer. Homosexuality is natural as green grass in summer, and it's high time we accepted that fact.

The birds do it. It's been described in 130 species of birds. The southeastern blueberry bees do it. Same sex pairs of animals kiss and caress each other with obvious affection and tenderness. Male pairs and female pairs form long-lasting pair-bonds and reject, threaten, even fight off potential opposite sex partners when they are presented with them. Same sex partners engage in almost every conceivable means of sexual expression throughout the animal kingdom.

It's high time we quit criminalizing something that is so normal, so natural, so harmless and so common among animals and recognize that what we call "sodomy" is really quite natural after all.

We're animals. And being animals, we should quit trying to pretend that we're not. What we call a "crime against nature" isn't unnatural, and it shouldn't be a crime.

For those wishing to learn more about homosexuality in animals:

There is but one book of any consequence on this subject:
Biological Exhuberance: Animal Homosexuality and Natural Diversity, by Bruce Bagemihl, Ph.D. This scholarly book is that rare combination of a good read and an overwhelmingly informative text. It has enough material in its 700-plus pages to satisfy the most demanding scholar, and at the same time is written in an accessible style that entertains the reader as well. Impeccably documented, the book makes an overwhelmingly convincing case for not only the presence of animal homosexuality, but also gives a thorough discussion of what is known about it. A balanced treatment, it has material that would be of considerable interest to both proponents and opponents of gay rights.

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Copyright 2000, by Scott Bidstrup. All rights reserved.
Revised 19/17/2000