The Antarctic fur seal was observed by South African scientists attempting to have sex with the king penguin on Marion Island, in the sub-Antarctic region. The incident was recorded in the Journal of Ethology.

The effort lasted forty-five fruitless minutes, according to the BBC.

Nico de Bruyn, of the Mammal Research Institute at the University of Pretoria, South Africa, said that the seal's motives, beyond the obvious, were unclear.

However, he speculates that it was frustrated behaviour on the part of an inexperienced seal unable to find a more suitable partner, or perhaps just a playful act that got carried away in the heat of the Antarctic moment.

"At first glimpse, we thought the seal was killing the penguin," he said, "but then we realised that the seal's intentions were rather more amorous."

Dr de Bruyn and a colleague witnessed the seal, a young adult male in good physical condition and weighing around 100kg (220lb), subdue the 15kg (33lb) penguin by lying on it.

The penguin, of unknown sex, attempted to escape by flapping and trying to stand, but was unable to as the marine predator thrusted its pelvis in an apparently unsuccessful attempt to achieve congress. After giving up the seal wandered off, ignoring its victim altogether.

Sexual harassment between members of the same species is common, and even between different species of mammal – as dog owners will know – but this is believed to be the first recorded example of such an assault between two classes, birds and mammals.