Robin McKie in The Guardian:
It was the sight of a young male Adélie penguin attempting to have sex with a dead female that particularly unnerved George Murray Levick, a scientist with the 1910-13 Scott Antarctic Expedition. No such observation had ever been recorded before, as far as he knew, and Levick, a typical Edwardian Englishman, was horrified. Blizzards and freezing cold were one thing. Penguin perversion was another.
Worse was to come, however. Levick spent the Antarctic summer of 1911-12 observing the colony of Adélies at Cape Adare, making him the only scientist to this day to have studied an entire breeding cycle there. During that time, he witnessed males having sex with other males and also with dead females, including several that had died the previous year. He also saw them sexually coerce females and chicks and occasionally kill them.
Levick blamed this “astonishing depravity” on “hooligan males” and wrote down his observations in Greek so that only an educated gentleman would understand the horrors he had witnessed. Back in Britain he produced a paper (in English), titled Natural History of the Adélie Penguin. However, the section about the animal's sexual proclivities was deemed to be so shocking it was removed to preserve decency. Levick then used this material as the basis for a separate short paper, Sexual Habits of the Adélie Penguin, which was privately circulated among a handful of experts.
In fact, Levick's observations turned out to be well ahead of their time.
More here.