Actually I read an article by Dr. Temple Grandin, the animal behavior expert, once, and she did refer to rapist roosters. Apparently, the instinctive way for chickens to mate is that the rooster does his little drop-wing-shuffle dance and the hen then squats and the roo mounts her. Her theory is that the breeding for larger animals has caused some of those instincts to be lost, and now the rooster just grabs the hen's head feathers and climbs on, whether the hen squats or not. She called them rapist roosters.
