Biological Exuberance; a new view of animal homosexuality

In his 1999 book Biological Exuberance – Animal Homosexuality and Natural Diversity – the biologist Bruce Bagemihl writes about same-
sex behaviors in a wide variety of primates, other mammals and in many bird species, explaining homosexual courtship, affection, sex, pair bonding and parenting. Same-sex behavior has been documented in over 450 species of animals; biologists point out that only a fraction of the more than a million species known to exist have been studied in any depth, so the number may be far larger. Bagemihl writes that western science has overstressed the importance of heterosexual sex for passing on genes and failed to notice many other kinds of sexual behavior – such as same sex mounting, necking (among male giraffes), oral sex and masturbation- mutual and solo.

Bonobos – pygmy chimpanzees (with whom we share over 99% of our genes) - are predominantly bisexual; females and males have frequent hetero and same-sex contact with each other, including with juveniles. Females also have sex during their pregnancies. Clearly their ‘exuberant’ sexual behavior has meanings beyond reproduction – anthropologists see it as beneficial to the group by creating tribal cohesion and preventing fights over food. These animals truly do make love not war.

Bagemihl points out that western science has attempted to explain animal homosexuality for over two hundred years but has had problems explaining behavior that is non-reproductive. However, from the point of view of biological exuberance, natural systems are driven as much by abundance as by limitations and practicality. Seen in this light, homosexuality and non-reproductive heterosexuality are “expected occurrences” – they are one manifestation of an overall “extravagance” of biological systems that has many other expressions.
Bagemihl. 1999. (Think of the peacock’s tail.)

In 2006, the Natural History Museum in Oslo opened the first-ever museum exhibition dedicated to gay animals. The exhibit , titled Against Nature?, showed photographs of the more than 1500 species (their count)where homosexuality has been observed – from insects to mammals. The curators stated that a greater understanding of how extensive and common this behavior is among animals could help to demystify homosexuality among people. You can see a few of the outstanding photographs of this exhibit by going to google : Against Nature? Exhibition in Oslo.

In today’s New York Times Magazine, April 4, 2010, the article The love that Dare Not Squawk its Name concerns new studies on animal homosexuality, mostly among seabirds. Careful observation of the Laysan Albatross, who nest in Hawaii, reveals that a third of nesting pairs are made up of two females. One or both mate briefly with a male and then return to their female nest-mate, with whom they may bond for many years. Taking off from Bagemihl’s theories, scientists are thinking that homosexuality must be seen as having different ‘purposes’ or manifestations in each species - it is a byproduct of reproductive sex, but cannot easily be explained by our current Darwinian model. New thinking is needed about the possible benefits of homosexuals to the family or the group, and also about homosexuality and bisexuality being a by-product of exuberant desire for sexual play.

Scientists studying animal sexual behavior have generally been careful not to extrapolate their findings to human society, but of course their findings have had an impact on the wider world. After publishing, the authors have been reviled by homophobes and cheered by many liberals and the GLBT community. The culture wars go on – and will undoubtedly be affected by new findings from other animals.
Sadja Greenwood, MD – back issues on this blog