According to the report on the Discover Magazine website, George Levick, a surgeon and zoologist, went on an Antarctic expedition with Captain Robert Scott (the Terra Nova Expedition) where he spent time observing and documenting the largest colony of Adélie penguins at Cape Adare (image above). Following his trip he published a story about the penguins for the general public as well as a scientific account. It was in this second document that he wrote “The crimes which they commit are such as to find no place in this book, but it is interesting indeed to note that, when nature intends them to find employment, these birds, like men, degenerate in idleness.” Yet he left out any details of the supposed “crimes” presumably because they were considered too explicit for the Edwardian times.
Researchers have now found a paper called, “The sexual habits of the Adélie penguin” that was preserved at the Natural History Museum. In this document, George Levick describes homosexual interactions, coerced sex (even with chicks), necrophilia and auto-erotic behaviors. Levick did not try to interpret the behaviors but his negative opinion of the penguins was certainly evident. Modern zoologists have suggested that perhaps the males were attracted by submissive poses other birds may have been exhibiting, which might have been similar to that of a receptive female. In fact, they found that male Adélie penguins would attempt to mate with any bird that assumes the mating position including females, males, chicks as well as rocks attached to a frozen penguin head.
You can read a quote from the book and see part of the document at Discover Magazine.