A relative of mine who used to live next to a lake has told me stories of duck gangrapes, where large groups of drakes forced themselves on a female, taking her neck in a stranglehold with their beaks as in the video, while taking turns to systematically rape her (the other drakes waiting in long lines for their turn). Among the animals where I know rape is common (pinnipeds, koalas, monkeys, apes, humans and perhaps dogs) I have never heard of anyone displaying this behaviour except for humans.
