Same-sex sexual behaviour is far more prevalent across the animal kingdom than research suggests — a new ϲʿӿ study finds researchers just overwhelmingly tend not to report it.
Since there’s not a lot of existing research on the topic, when researchers witness same-sex behaviour in the field, they often believe it’s an anomaly too rare to be worth reporting. That’s why about half of surveyed experts said they chose not to collect data on or report the behaviour, though the majority observed it.
“We realized some species we had observed engaging in same-sex behaviour were not included in other published reports and we wondered how often other researchers were witnessing it and also not publishing,” says study co-author Karyn Anderson, a PhD candidate in the department of anthropology at ϲʿӿ. “We decided the best way to get at this information was to go directly to the source.”
The study, , surveyed 65 mammologists, wildlife biologists and ecologists who’d studied a range of mammals in the field, from monkeys to elephants. They’d seen same-sex behaviour — defined as mounting or other genital contact — in almost 80 per cent of the 54 species they completed surveys on, yet about 80 per cent of those researchers never published their data.
There were even 17 species that had no research stating they engaged in same-sex behaviour, but that experts had witnessed doing just that.
“Some respondents reported observing encounters that lasted close to an hour, while others said they had only seen it a few times or very briefly in many years of observation,” says Anderson, who is completing her PhD in the lab of Associate Professor Julie Teichroeb.
When asked why they chose not to collect or publish their findings, none of the researchers reported a discomfort with homosexuality or any prejudice against it. The study collected demographic information on its respondents too, though nothing was found to impact likelihood of recording or reporting, including their career stage, the animals they studied, and whether they identified as part of the LGBTQ+ community.
Another major reason for the holdout, reported by about a quarter of respondents, was that they simply had other research goals they needed to prioritize, or they weren’t leading the studies and didn’t determine what was included.
Responses also backed the theory that popular ideas about the role of same-sex behaviours have led researchers to lump it into other categories in their data collection, with many recording it as instances of establishing dominance, playing or creating social bonds. Only 22 per cent of respondents classified it as a unique behaviour.
The study does note there’s a bias deterring researchers — one against anecdotal evidence. Most researchers reported they chose not to record or report not only because they thought the behaviour was rare, but because existing evidence is too dominated by eye-witness accounts. Yet most animal behaviour research has evolved when what starts out as stories from the field is later tested and verified by objective, repeatable studies.
Anderson notes this bias is a more recent feature of Western wildlife biology, one not necessarily shared in other areas of animal behaviour research. She points out Japanese primatologists, who tend to view researchers’ narrative accounts with more reverence.
“At some point anecdotes were no longer considered rigorous enough for some publications, but they can tell us important things about overarching trends,” she says. “One monkey engaging in same-sex behaviour isn’t necessarily going to tell us a lot about its evolution or function, but if all animals engage in it, that’s a whole different story.”
The study references that other misconceptions of “rare” behaviours have been disproven once researchers began studying them in a more structured, formal way, such as when feed their young by chewing up and spitting out their food, akin to birds.
“I hope this encourages scientists to publish on their observations of behaviours that they perceive to be rare,” Anderson says.