"The strange case of the homosexual necrophiliac duck pushed out the boundaries of knowledge in a rather improbable way when it was recorded by Dutch researcher Kees Moeliker."
"Ducks behave pretty badly, it seems. It is not so much that up to one in 10 of mallard couples are homosexual - no one would raise an eyebrow in the liberal Netherlands - but they regularly indulge in 'attempted rape flights' when they pursue other ducks with a view to forcible mating. 'Rape is a normal reproductive strategy in mallards,' explains Mr Moeliker."
"As he recounts in his seminal paper, 'The first case of homosexual necrophilia in the mallard anas platyrhynchos,' he was in his office in the Natuurmuseum Rotterdam, when he was alerted by a bang to the fact a bird had crashed into the glass facade of the building. 'I went downstairs immediately to see if the window was damaged, and saw a drake mallard (anas platyrhynchos) lying motionless on its belly in the sand, two metres outside the facade. The unfortunate duck apparently had hit the building in full flight at a height of about three metres from the ground. Next to the obviously dead duck, another male mallard (in full adult plumage without any visible traces of moult) was present. He forcibly picked into the back, the base of the bill and mostly into the back of the head of the dead mallard for about two minutes, then mounted the corpse and started to copulate, with great force, almost continuously picking the side of the head.'"