There is a common belief that homosexuality is 'unnatural' - a condition only known to fallen humanity. The rest of the animal world allegedly knows no such practice, as their only motivation for mating is the age old instinct for procreation. But is that really the case? Numerous studies have shown that same-sex couplings occur among animals, both in the field and in the lab.1 Male-male and female-female sexual activity has been observed in numerous reptilian, avian and mammalian species, with arrangements ranging from short-term trysts to stable long-term pairings.2
Biological Exuberance (St Martin's Press), by linguist and cognitive scientist Bruce Bagemihl, mentioned 94 bird species known to engage in homosexual behavior. One such species is geese (Anser Anser) - about 15 percent of pair-bondings between geese are between males, and some relationships have been documented to last over 15 years. A male bonded to another male shows 'grief' after his partner dies, just as males bonded to females do.3
Homosexuality couplings in nature do not necessarily exclude reproduction. For example, among swans, a female may mate with a gay couple and then leave her eggs for them to raise. Male couples are documented to have a higher success rate in fledging their young compared to male-female couples (80% vs 30%).4
Both male and female homosexual behavior has been reporrted in over 100 mammalian species, including primates.5 Female-female sexual encounters are well-documented among bonobos (pygmy chimpanzees), and appear to serve a social function of cementing 'alliances' and cooperation among females.6
The purpose of pointing out the existence of homosexual behavior in both wild and domestic species is not to 'promote' homosexuality or persuade the opponents of homosexuality to change their minds. Each person is entitled to his/her own moral views. We are merely suggesting that opponents of homosexuality should probably not use 'nature' as an argument.
As for whether one should judge homosexuality as moral or immoral, this should be a choice based on personal morality, not arguments about 'nature'. Gay rights activists shouldn't rely on the 'nature' argument anymore than gay rights opponents should. Just because something occurs in the natural world doesn't make it 'right' for humans. There are 'naturally-ocurring' in the animal kingdom which are considered immoral by humans universally, said practices being theft and murder. And there are many 'natural' practices that even members of the religious right in the West would consider immoral, despite their occurence in the animal world - such being rape, polyandry, polygyny, incest and adultery. I am not at all implying that homosexuality should be put in the same box as incest or polygamy; merely stating the fact that humans have created their own moral standards quite independently of the behavior of other animals, and that those who take a certain stand about homosexuality should consider using other arguments to bolster their views.
May 1999 (updated 2005)