Weddell seals lie atop ice at Cape Denison, Commonwealth Bay, East Antarctica, in this picture taken January 1, 2010.
Weddell seals lie atop ice at Cape Denison, Commonwealth Bay, East Antarctica, in this picture taken January 1, 2010. REUTERS/Pauline Askin Reuters

Seals in Antarctica have been trying to mate and forcing themselves on king penguins. The shocking sexual assault by the seals are changing the way animal experts explain such acts.

According to Discovery News, it was thought, initially, that sex between different species was an error, a result of mistaken identity. The latest issue of the journal Polar Biology documented that male seals sexually assaulted penguins.

Senior author from the University of Pretoria, Nico de Bruyn, wrote in the journal that the rapes of penguins by the seals might either by an extreme case of reproductive interference or might be learned behaviour that was associated with a kind of reward. It could be a learned behaviour, which was fueled by the hormones in the males that ultimately weakened the overall reproductive fitness of both, the seals and the penguins.

According to Emily Burdfield-Steel, a researcher at the University of Jyväskylä in Finland, when individuals of one species engaged in activities relating to reproduction with another, then it was a process called reproductive interference. She added that reproductive interference leads to reduction of fitness in either one or both the species.

It was found that the fitness of the penguins was reduced to a great extent and at least one of the victims, would bleed between its legs. Mating in seals required time and energy and when they mate with penguins, the seal population would be affected as there would be no offspring. The only reward would be the immediate sexual satisfaction of the male.

Describing one of the seal-penguin encounters, de Bruyn wrote that the seal ran up to the penguin and bumped it down. He wrote that the seal lay on top of the penguin. The erect penis of the seal was visible and it would thrust its hips. A video of one of the encounters on Mario Island, north of Antarctica, was captured and the graphic and disturbing footage has gone viral.

De Bruyn had first come across a seal copulating with a king penguin six years ago on Marion island. This bizarre behaviour of the seals was not noted earlier despite the island being a subject of study for almost 35 years.