7 Penguin Secrets That Were Hidden for a Century

Turns out penguins may not be the cute and cuddly creatures the world perceives them to be.

Not all black and white

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The world’s first penguin biologist George Murray Levick was marooned for almost a year in 1910 on Cape Adare on Antarctica, the site of the world’s largest Adelie penguin colony, where he conducted the world’s first serious study of penguins. Many of his observations—but not all of them—were published in his book, Antarctic Penguins: A Study of Their Social Habits. Nearly a century later it was revealed that Levick’s most shocking observations about the mating behavior of the penguins were left out of his published work. “It would take other scientists, myself included, the better part of those one hundred years to unearth the true picture about penguins, which Levick had been the first to see,” notes award-winning scientist Lloyd Spencer Davis, author of A Polar Affair. Davis shares some of Levick’s observations of the penguin as well as his own insights about the proclivities of penguins. Take a look at these penguin pictures that will melt your heart.

Penguins engage in same-sex behavior

Levick describes in his zoological notes the reciprocal homosexual mountings between two male Adelie penguins, whereby one mounts the other, and then they swap places and repeat the performance. He refrained from referring to any of this in his book about penguins. “It would be over 70 years until I would come along, observe the exact same phenomenon between consenting male penguins, and publish what I thought were the ‘first’ observations of homosexuality in wild penguins,” says Davis.

Penguins are not monogamous

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Levick’s notes record several instances of penguins mating with more than one partner during the breeding season. Levick kept the penguin mate swapping that he observed out of his public writings. It was not until the 1980s that, while watching penguins intently, Davis and other penguin scientists observed that swapping partners was a frequent occurrence during the courtship period. “It could sometimes seem like a penguin version of musical chairs, whereby females may move from one nest and male to another, two, or even three or more, times,” says Davis. Find out 27 more facts about animals you have all wrong.

Divorce occurs in penguin colonies

Davis discovered, depending upon the season, up to a third of Adelie penguins may pair up with a new partner from one season to the next, despite both members of the pair surviving the rigors of the Antarctic winter and their long migration. He notes the irony that the film March of the Penguins, about Emperor penguins, was presented as an example of an animal that represents “good values” as Emperor penguins are even less disposed to “mating for life” than are Adelie penguins, with about 85 percent of them divorcing from one season to the next. Still, other species of penguins are some of the 11 animals that mate for life.

Some penguin sex is not consensual

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Levick’s most shocking revelations concern the non-consensual sex. “His most extreme observation is of an injured female enduring copulation by three successive males as she struggles to get away,” says Davis. Davis has not witnessed this behavior in his 40 years of studying penguins; however, he believes Levick’s observations. “They fit with male penguins lacking any discrimination and copulating with anything that they can during the mating period,” Davis says. “My postdoctoral fellow and I discovered that they would readily mount a stuffed toy penguin if given the opportunity.”

Some penguin partners aren’t even alive

Levick recorded in his notes several examples of male penguins mounting and copulating with the corpses of dead penguins. Davis observed this behavior as well. “It is no doubt part of the same phenomenon, whereby males can produce millions of sperm with every ejaculate. Hence, the cost to them of an inappropriate mating is negligible,” Davis says. “Whereas females produce only two eggs each breeding season, which makes it imperative that they are choosy about mating with an appropriate partner in order to be successful.”

Female penguins find sneaky ways to get pregnant

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Davis and his postdoctoral fellow observed penguins around the clock and discovered that females sometimes sneak away from their partner to copulate with another male, then return to their partner. “Male and female penguins must both share parental duties to look after the eggs and chicks if they are to be successful. Yet up to 8 percent of male penguins are infertile, so it may not be quite enough for success to have a male that performs his paternal duties well. By having a sneaky copulation with another male, females might be ensuring that at least one of their eggs is fertilized,” says Davis. Find out the penguin species that could disappear by the end of the century.

“Currency” is sometimes exchanged for sex in the penguin colony

Davis and his team discovered instances where females would have sex with an unpaired male in exchange for a stone. The female would then take it back to her own partner and nest. “Stones are used by the penguins to line their nests upon the ground, keeping the nest well-drained and the eggs clear of water from melting snow. There is much competition within a penguin colony for suitable stones and they may be regarded, to all intents and purposes, as the ‘currency’ of the colony,” says Davis. Find out 60 fun facts about animals you didn’t know before.

How the penguin proclivities came to light

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Two years after returning from the Antarctic and one year after publishing his book about penguins, Levick wrote a short paper outlining the lurid side of penguins. However, he was not allowed to publish it. Instead, 100 copies were produced and circulated internally at the British Museum of Natural History. Nearly all were promptly discarded. Nearly a century later, in 2012, Douglas Russell, the senior curator of birds’ eggs and nests at the Natural History Museum (the renamed British Museum of Natural History), would discover a surviving copy of the unpublished manuscript and Levick’s observations about the sexual proclivities of penguins would remain censored no more. Learn more surprising penguin facts.

Stacey Marcus
Stacey is a writer for top regional and national outlets covering trivia, quotes, and Jeopardy. She's been published in Boston Magazine, Boston Common Magazine, Mental Floss, New England Living, and Playboy.com.
A New England native, she's an expert in all things East Coast and has traveled extensively to cover destinations for travel outlets.