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Two male African elephants exhibit same-sex sexual behavior in Tsavo, Kenya.
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Same-sex sexual behavior has been observed in more than 1,500 animal species, but a new study finds it is massively underreported by researchers.
Observations of these same-sex behaviors in animals, such as intercourse and genital touching, date back to the 1700s and 1800s. However, research on the subject did not progress until the 20th and 21st centuries.
In a study published Thursday in the journal PLOSOne, a team of researchers from the University of Toronto, Northwestern University and the University of Warsaw found that experts who study animal behavior underestimate and rarely publish their observations of same-sex sexual behavior.
The study surveyed 65 experts and found that 77% of them had observed same-sex sexual behavior in the species they studied. But only 48% have collected data on these behaviors, and even fewer—just 18%—have published articles about these findings.
“Many respondents reported that they lack data recording or publishing on the SSSB [same-sex sexual behavior] It was because of the perception that it was very rare,” Karyn Anderson, a PhD candidate in evolutionary anthropology at the University of Toronto who led the study, told CNN. “Looking at it more broadly, we found that it was very commonly observed by our survey participants.”
The view that this sexual behavior is rare in the animal kingdom has been and continues to be used in debates about the ethics of human homosexuality, the study noted.
Anderson says their study, like others on same-sex sexual behavior in animals, found that the behavior is actually “widespread and natural in the animal kingdom.”
David Hecker/DDP/AFP/Getty Images
Two female penguins stand in front of a cavity where two pairs of male penguins “Sechs Punkt” (Six Point) and “Schraegstrich” (Slash) cuddle at Bremerhaven Zoo, home to three pairs of homosexual male penguins, in February 2005. four female penguins penguins from the Swedish zoo last January, the males still show no interest in them.
Nevertheless, homosexual behavior is still being discovered in different species. In 2018, the first report of sex between male spider monkeys was recorded. That same year, two male Gentoo penguins made headlines for “adopting” an egg left by a male-female penguin pair.
This field appears ripe for future research — of the species identified in the survey as engaging in same-sex behavior, nearly 39% had no previous reports of this behavior, according to the authors.
Josh Davis, science writer for the Natural History Museum in London and author of “A Little Gay Natural History,” wasn’t surprised by the study’s findings, but says it’s “pretty exciting” to have the data to back up the numbers. .
“Homosexual behavior has been officially recorded in about 1,500 animal species, but I think for a long time most people have suspected that this is most likely a huge underestimate,” he told CNN. “Because it’s found in almost every branch of the evolutionary tree… from bugs and butterflies to lizards and squirrels.”
By identifying this research gap, Anderson hopes that other mammalogists will be encouraged to publish their studies of same-sex sexual behavior.
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Two adult male tree frogs (Pelophylax kl. esculentus) mating on water lily leaves in Luisenpark, Germany.
While the authors hypothesized that discomfort or socio-political reasons may contribute to the underreporting of same-sex sexual behavior, this was not the case among the researchers they surveyed.
Instead, respondents told them it might be because this sexual behavior was rare or not a research priority for their lab. Most of their observations would be considered “anecdotal” rather than the result of systematic study, perhaps making scientific journals less inclined to publish their findings.
Davis added that there are other obstacles that stand in the way of documenting same-sex behavior among animals.
“Historically, researchers were definitely concerned that if they published about this behavior, they might be associated with this behavior,” he said, although that “has gotten better over time.”
Another challenge for researchers is that when observing sexual activity in species, the sex of the animal may not always be clear. “There’s an underlying assumption that when they see it, they’re watching a man and a woman,” Davis said.
“The biggest takeaway from this research is that same-sex sexual behavior is widely observed but not widely reported in mammals,” explained Anderson, who added that “this could be true for other behaviors that are perceived as rare but have been found . to be more common when we look at it on a larger scale.’