Gay animals are more common that we thought! Study claims same-sex behaviour in the wild is underreported by biologists
- Gay animal observations may not get published due to publishing bias
- READ MORE: Gay behaviour is the norm for most animals, study finds
Gay behaviour in animals was first observed more than a century ago – and it's long been considered unusual in species.
But a new study reveals it's far more common that we've been led to believe.
Experts claim that homosexuality in the animal kingdom is 'widely observed' by biologists but left underreported.
From mounting to penetrative sex and 'genital-oral contact', animals engage in a variety of 'widespread and natural' sex behaviours in the wild.
However, these observations may not get published due to a 'publishing bias against anecdotal evidence', the new study explains.
Experts claim that homosexuality in the animal kingdom is commonly observed by biologists but widely underreported. Pictured, gay bhevaiour between two mallard ducks
Same-sex sexual behaviour occurs 'more frequently than what is available in the published record', experts say. Pictured, two male African golden wolves (Canis anthus)
The research was led by Karyn Anderson, a graduate student in anthropology at the University of Toronto, Canada.
'Same-sex sexual behaviour occurs more frequently than what is available within the published record,' Anderson and colleagues say in their paper.
'This may be due to a publishing bias against anecdotal evidence.'
It was back in 1896 that French entomologist Henri Gadeau de Kerville published one of the first scientific illustrations of animal homosexuality.
His drawing, depicting two male scarab beetles copulating, set the stage for animal observations throughout the 1900s.
And during an expedition to Antarctica in 1911-12, British explorer George Murray Levick observed same sex behaviour in penguins, as well as rape and necrophilia.
In 1896, French entomologist Henri Gadeau de Kerville published one of the first scientific illustrations of animal homosexuality. His drawing depicted two male scarab beetles copulating (pictured)
The researchers then set about tracing the evolution of this behaviour, which scientists call the 'Darwinian paradox'. That is - why do animals practice same-sex sexual activity when it has no obvious evolutionary benefit and could lead to extinction if all members of species practice it?
But his paper detailing his observations was refused publication at the time for being too 'indecent' (and it wouldn't get published for another 100 years).
Yet still, Anderson and colleagues point out, the belief persists that homosexuality is not the norm in the animal kingdom.
For their study, they conducted an online survey of 65 wildlife researchers whose work focused on observations of different species.
Observations included monkeys, squirrels, mongooses, elephants, mole-rats, coati (a member of the raccoon family) and orca (the killer whale).
In all, 76 per cent said they had observed same-sex behaviour in their study species, but only 48.2 per cent) had collected data on it, and ever fewer (18.5 per cent) had published papers on it.
Such behaviour included 'mounting, intromission, and genital-oral or manual-genital contact' with members of the same sex, the team say.
It shows researchers widely observe yet seldom publish about same-sex sexual behaviour in primates and other mammals.
This is because it is perceived to be too rare to represent the species as a whole, or because it was not a research priority of their lab.
Same-sex displays may help increase social bonding and reduce conflict. Pictured, meerkats in an enclosure of the zoo Hellabrunn in Munich
In the black swan, males pair up and raise stolen eggs from females - although this is different from displaying gay sexual activity
'This appears to be due to a perception of researchers that same-sex sexual behaviour is very rare,' Anderson told the Guardian.
'We found, however, that it was commonly observed by our survey participants.
'One thing I think we can say for certain is that same-sex sexual behaviour is widespread and natural in the animal kingdom.'
Interestingly, there was no correlation between a researcher identifying as LGBTQ+ and recording data on, or publishing on, same-sex sexual behaviour.
Experts led by Spain's Estación Experimental de Zonas Áridas reviewed the scientific literature related to gay behaviour in animals and created a database of their findings. They found that gay behaviour is equally common in both female and male animals (pictured)
In biology, something known as the 'Darwinian Paradox' may have led researchers to believe that animal homosexual activity is rare.
The paradox asks: why do animals practice same-sex sexual activity when it has no obvious evolutionary benefit and could lead to extinction if all members of species practice it?
In their new paper, Anderson and colleagues say: 'The notion of SSSB [same-sex sexual behaviour] as a rare, "Darwinian Paradox" have persisted throughout the literature, despite widespread reporting of SSSB across all major animal clades.'
Last year, an analysis revealed that same-sex displays were more likely to evolve in social species, which led them to conclude that such behaviour helps establish and maintain positive social relationships.