As a psychology student at Tulane University, I took a couple of independent study courses observing animal behaviour at Audubon Zoo, near campus. One semester, I studied the mating behaviour of the scarlet ibis, a wading bird common in marshes and estuaries. Like other species of birds, the ibis is seasonally monogamous. For weeks, I watched seven pairs go through the process of nest-building, courting and mating. Right on schedule, all but one pair stopped sexual and nest-building behaviour within days of each other and settled in for the incubation period. My interest was piqued by the behaviour of one particular pair that kept building their nest, as well as mating.
A couple of weeks passed and their nest continued to grow. One day, I saw the bird I thought I had identified as “female” mounting the male, but did not record the behaviour, thinking that I must have gotten confused. More time passed, and by now the nest was absolutely stunning. – about twice the size of the others, and much more beautiful – it was a perfect nest. Then I saw it again; my birds had switched roles while mating. At this point I went to my professor and told him what was going on. His rather nonchalant response was “Oh, sure, it’s very likely that they are both male. Homosexuality is common in certain species of birds.”
“Of course”, I thought to myself, “leave it to the gay birds to have a fabulous designer nest”.
The quote above, from Christian de la Huerta’s “Coming Out Spiritually“, is instructive. Although the account is that of a simple piece of college coursework, it neatly illustrates some of the many ways in which even experienced, professional researchers commonly mistake the sex of the animals they are observing – and so underestimate the extent of same sex relationships in the animal world.
The non-conforming pair de la Huerta eventually identified as comprising two males, but initially he thought they were a male and female – and had incorrectly identified one of the birds as the female. He does not say on what grounds he made this identification, but there is a clue when he describes the first occasion when his identification was challenged – he saw the “female” bird mount the other. It is clear that the sex identification he made originally was based on no more than the respective positions they adopted. On this basis, the one doing the mounting was assumed to be male, the one being mounted was taken to be the female. In some animal and bird species, sexual dimorphism is pronounced, and correct identification is easy. But in many other species, correct identification is much more difficult, especially when observing from any distance. If the sexual identification is based exclusively on the sexual role adopted, then inevitably only “heterosexual” coupling will be recorded – because any same sex coupling will be incorrectly recorded as involving a “male” and a “female”. (What should be recorded is simply a “mounter” and a “mountee” – sex indeterminate).
The second instructive consideration is that even after seeing the evidence of his mistake, he did not initially believe the evidence of his own eyes, preferring to assume that he had made an incorrect identification. This too is typical of the experience of many researchers – they are so conditioned to expect sexual behaviour to be between a male and a female, that observations to the contrary are initially disbelieved or treated with suspicion. It was not until he saw incontrovertible evidence, with the birds shifting roles in front of him, that he realized that what he was seeing was not a standard heterosexual pair. Even then, he did not immediately reach the obvious conclusion, and record a same- sex couple. Instead, he first sought guidance from his supervisor.
This is where the story becomes hopeful. The supervisor was able to confirm that it is now known that homosexual mating is commonplace among some bird species. As this becomes more widely recognized, so more researchers will be able to trust their own observations, and to correctly interpret and record what they are seeing.
Expect the scientific journals in future to carry many more reports of animal homosexuality observations than they have done up to now.
Roughgarden, Joan: Evolution’s Rainbow: Diversity, Gender, and Sexuality in Nature and People