It seems that the Antarctic may be a hotspot for documenting disturbing animal sex acts. Many years ago, British explorer George Murray Levick caught Adélie penguins engaging in all sorts of debauchery, such as necrophilia, sexual coercion and sexual abuse of chicks. Now, scientists have observed fur seals trying to have sex with penguins. While these observations may not be as shocking as what Levick documented, they are unusual nonetheless.

This bizarre sexual behavior was actually first documented in 2006 when scientists spotted a fur seal trying to copulate with a king penguin on Marion Island, a remote and mostly barren island in the sub-Antarctic. At the time, the researchers speculated that the incident may have occurred because the seal was frustrated or sexually inexperienced. Alternatively, they suggested, it could have been an act of aggression as the seal attempted to protect its territory. Or it simply could have been a playful act that turned sexual.

Upon returning to the island to continue wildlife observations, scientists observed the strange act a further three times, which took them by surprise to say the least.

“Honestly I did not expect that follow up sightings of a similar nature to that 2006 one would ever be made again,” said lead scientist Nico de Bruyn, “and certainly not on multiple occasions.”

As described in the journal Polar Biology, the team observed young male Antarctic fur seals sexually coercing (using force to achieve mating) king penguins on three separate occasions. The gender of the penguins was unknown, but they appeared to be in good health.

All four acts observed so far seemed to follow a similar pattern where the seal chases, captures and then mounts the penguin. The seal then attempted to copulate with the penguin several times, with each effort lasting around five minutes. Of course, all of this harassment was tiring, so the seal would take a break in between attempts.

Like most birds, penguins don’t have external genitalia and instead possess an opening called a cloaca. They mate by pressing these organs together in what is known as a “cloacal kiss,” in which the sperm is transferred to the female. Traumatically for the penguins, some of the seals were thought to have successfully penetrated the victims’ cloacas during the act as blood was observed around the area afterwards. Although seals often catch and consume penguins, in all but one of the acts the seal let the penguin go afterward. After the most recently documented incident, however, the seal killed and ate the penguin.

Why fur seals are engaging in these unusual activities is puzzling. While the scientists can only speculate, it could possibly be related to hormonal surges experienced during the breeding season. Alternatively, penguins could merely be an easy target to practice copulation with.

Although the harassment is difficult to explain, the possible increase in frequency seems to suggest that it may be becoming a learned behavior on the island. It is known that seals are able to learn from each other, so it is possible that it is spreading through observation. The researchers would therefore like to continue their observations to verify this.

[Via the BBC, Polar Biology and the Mirror]