There are multiple reasons for this underreporting. Historically, early career researchers feared being associated with these behaviors, leading to professional repercussions. More recently, the publishing model in scientific journals has shifted, making it less likely to publish short observational studies. Additionally, moral and cultural biases have influenced the way these behaviors are perceived and reported.
Levick used a Greek cipher to obscure his observations of penguin sexual behaviors, including forced copulation, necrophilia, and homosexual acts, to prevent prying eyes from reading and possibly being disturbed or scandalized by the content.
Same-sex sexual behavior has been officially recorded in about 1,500 species, spanning the entire tree of life from orb-weaved spiders to Western gorillas. This figure is likely a gross underestimate, as the behavior is observed across various branches of the evolutionary tree.
One of the earliest recorded examples is from 1834, when researchers discovered two male cockchafer beetles engaging in same-sex sexual activity. This led to a heated debate among entomologists and was documented in a drawing by August Kelch in 1896.
Same-sex behaviors can serve various purposes beyond reproduction. For example, in bonobos, these behaviors promote social cohesion, stress relief, and social bonding. In black swans, male-male pairs maintain larger territories and successfully raise more chicks compared to male-female pairs.
Historically, same-sex behavior in animals was often seen as unnatural or morally wrong. However, as more studies have emerged, the understanding has shifted. Now, it is recognized that these behaviors can serve multiple roles such as social bonding, stress relief, and even pleasure, challenging the Darwinian paradox that sex is solely for reproduction.
The case of the 'lesbian seagulls' in the 1970s, where female seagulls were observed forming pairs and raising larger clutches of eggs, became a significant point of controversy. It landed in the middle of the queer revolution in the US and was used in political debates about the nature of homosexuality, particularly by those arguing that it was unnatural.
Some people argue against the relevance of same-sex behavior in animals to human sexuality by invoking the naturalistic fallacy, which states that just because a behavior occurs in nature, it doesn't mean it should be practiced by humans. They often cite other natural behaviors like cannibalism or infanticide to support this argument.
The key takeaway from Josh Davis's research is that nature is endlessly diverse and that there are few hard and fast rules. This diversity challenges traditional views and highlights the complexity and variety of sexual behaviors across the animal kingdom, suggesting that anything goes in nature.
In this episode from July, Ian Sample talks to Josh Davis, a science writer at the Natural History Museum in London and author of the book A Little Gay Natural History. A study published in June 2024 suggested that, although animal scientists widely observe same-sex sexual behaviour in primates and other mammals, they seldom publish about it. Josh considers why this might be and describes some of his favourite examples of sexual diversity from the animal kingdom.. Help support our independent journalism at theguardian.com/sciencepod