The remote Marion island was the scene of the first, bizarre incident. Antarctic fur seals typically eat krill, fish, squid and the occasional bird—including penguins. But this particular young adult male was not eating the king penguin. He was attempting to have sex with it, according to the BBC.
Now, the same behavior has been captured on film three more times and reported in the scientific journal Polar Biology. And the researchers are puzzled. The first instance could have been chalked up to a sexually inexperienced male targeting the closest thing to a female seal he could find—a case of misdirected mating. Or it could have been a hunt gone strange. But the three new reports suggest that sex with penguins might be a behavior that is spreading among fur seals in the region, writes Matt Walker for the BBC.
In all the cases, a larger seal chased down a penguin, mounted it and tried to copulate. Walker reports:
Male and female penguins mate via an opening called a cloaca, and the seals are thought to have actually penetrated the penguins in some of the acts, which were caught on film by [research team leader William A. Haddad].
In three of the four recorded incidents the seal let the penguin go. But on one of the more recent occasions, the seal killed and ate the penguin after trying to mate with it.
"I genuinely think the behavior is increasing in frequency," says Nico de Bruyn, a researcher at the Mammal Research Institute at the University of Pretoria, South Africa. He thinks that seals may see other males trying to have sex with penguins and imitate them—either for practice or because they have no other way to release sexual frustration. The individuals they recorded were all too young to have their own harems of females.
This isn’t the first time we’ve found animals engaging, or attempting to engage, in interspecies coitus. Researchers have observed male sea otters in Monterey Bay capturing and copulating with baby harbor seals and killing them in the process. And dolphins are notoriously violent in their sexual acts. Males will gang up on females and go after humans.
It’s difficult not to let human morals color our perception of such acts. Even scientists, who strive to note these behaviors objectively, sometimes fall short when detailing the varied sexual behavior in the animal kingdom. George Murray Levick, who accompanied the 1910-1913 Scott Antarctic Expedition, never published his findings about Adélie penguins and attempted to obscure them by writing in Greek. The behavior that so shocked him was males copulating with other males, injured females, chicks and corpses, reports Brian Switek for Slate.
Somehow, when animal sexual acts result in offspring, the thought is less off-putting. Successful interspecies breeding is called hybridization and has given us pizzlies in the wild (polar bear and grizzly hybrids), mules and zonkeys domestically and … modern humans. Neanderthal genes left in our genome are testament to that interbreeding.
But ascribing human motivation to these behaviors isn’t correct. "There is no animal that is made of rainbows and kisses and goodness all the way through," Switek writes.