In Tasmania, the Devil Now Faces Its Own Hell - New York Times

"Devil sex turns up the volume. In March and April, males engage in vicious, blood-soaked combat, said Dr. Menna Jones, a wildlife biologist who also works in the environment department. Females select 'big butch dudes,' Dr. Jones said, and allow themselves to be dragged by the scruff of the neck into a burrow. There they scream and fight for several days, mating many times for hours at a time. At the end of such bouts, the male thrusts his sperm into the female every two minutes."