New research reveals same-sex couples in 1,500 animal species

Same-sex couples have been reported in penguins, giraffes, anteaters and monkeys - to name just a few - as ITV News Consumer Editor Chris Choi reports

ITV News has spoken to researchers at the heart of a ground-breaking new study, which has some surprising findings.

Scientists based in the UK are observing bisexual monkeys that live on a small island of around 32 acres just off the eastern coast of Puerto Rico.

A team from Imperial College London has made some startling discoveries. The majority of male monkeys in this group of around 2,000 animals have taken part in sex with other males.

It has led to a fascinating question, which the zoologists are calling the "Darwinian paradox".

Evolution is understood to dictate that genes and behaviour that give an advantage will be passed down the generations.

But how can there be any reproductive benefit in homosexual encounters like these that can't lead to offspring? The answer may surprise you.

Professor Vincent Savolainen, who is leading the research into gay macaque monkeys, told ITV News: "The males that have sex with each other also fight together against other animals.

"So this way they may have more access to females and then have more babies. So despite the fact that they do a lot of homosexual sex, they are in effect bisexual and get some adaptive advantage - even possibly on their own reproduction."

The isolation of this colony makes it ideal for study, because every animal's parentage and genetics can be tracked.

Each has an identification tattoo making is easier to track individuals. Researchers take a small boat to the island and spend seven-hour shifts observing the monkeys.

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Their discoveries are adding to our understanding of what behaviours can be defined as natural in the wild - and the complexity of reasons for such gay activity.

The research into bisexual apes is part of an expanding picture of sexual diversity in the animal kingdom.

New work at the Natural History Museum presents evidence that same sex behaviour is widespread throughout almost every branch on the tree of life.

Zoological researchers say gay couplings have been recorded in more than 1,500 species.

Many scientists believe this aspect of natural history has been long-neglected. First observed in 1912, it took a century for reports of homosexual activity among penguins in the Antarctic to be published.

Edwardian Britain wasn't ready for such revelations and that attitude continued for many years.

Things are now changing fast. At London Zoo there is a well informed and fully researched alternative to the old "don't talk about it" approach.

The zoo holds regular Zoo Nights - adult-only events where discussion of animal sexuality is one of the highlights.

Rather than brushing same-sex activity under the carpet, London Zoo celebrates this aspect of nature's diversity.

It seems that what we were all told about the birds and the bees may not have been the full story.

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Words by Josh Davis, Natural History Museum

For centuries scientists have wondered why animals exhibit homosexual behaviours.

My new research flips this question on its head by showcasing the astonishing diversity of sexual behaviour, biology and reproduction that can be found in the natural world.

As part of this, it is revealing how historically scientists and researchers have often covered up, over-looked and disparaged these behaviours.

For the past five years I've been researching homosexual behaviours in nature, but despite there being more reports on these behaviours than ever before they're still often seen as being "unusual" or "comical".

Whilst homosexual behaviour has only been officially recorded in around 1,500 species, this figure is likely a massive underestimate. This is because it can be found in pretty much every branch of the evolutionary tree - from beetles and butterflies to turtles and squirrels.

Instead, it seems more likely that most species exhibit some form of same-sex behaviour, and it is more unusual to be a purely heterosexual species.

But for hundreds of years these behaviours have often been covered up. Onboard Scott's fateful expedition to the South Pole was the surgeon and naturalist George Murrey Levick.

During this trip he became the first person to observe the full breeding cycle of the Adelie penguin, but he also observed sexual behaviours he couldn't understand, including sex between the males.

On his return to the UK, Levick tried to publish these findings in a report on the penguin's biology.

But before going to print the section on their sexual activity was excised. Instead, 100 copies of the section were printed privately with the bold header "Not for publication" and distributed among a select group who were allowed to see it.

This all remained a secret, until a century later when a copy of the pamphlet was discovered sandwiched between the pages of a book and finally published in full in 2012.

This under-reporting of homosexual behaviours in animals is not limited to the past. A new study published in the journal PLOS One found that whilst 77% of mammal researchers surveyed had recorded same-sex behaviour in their study species, only 18% had published on it.

There are probably a few reasons why scientists have been under-reporting homosexual behaviours in animals. Historically, there were definitely fears that if a researcher were to publish on these behaviours they might in turn get associated with them, but in modern times it looks as if there are other factors in play.

Part of the problem highlighted by the study is a bias in science journals against publishing short papers on occasional and anecdotal observations, for which homosexual behaviours often are.

But another issue is the inability to secure funding to study same-sex behaviours in their own right.

By showing how common, widespread and fascinating these behaviours are, I hope to give an insight into an aspect of diversity in the natural world that is still struggling to get the recognition it needs.

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